All Wiring Diagrams for GMC Cab & Chassis K1997 3500

AIR CONDITIONING

5.0L

5.0L (VIN M), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, near egr breakout)
• (engine harness, in fuse-relay center breakout)
• (engine harness, near fuse-relay center)
• (engine harness, near underhood lamp breakout)
• (exc 4.3 l)
• (fwd lamps harn, 5cm from right headlamp breakout)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 28 cm from cluster breakout)
• (i/p harness, in hvac connector breakout)
• (rear hvac control harness, 5 cm from hvac logic module breakout)
• (right side of engine)
• A/c comp mini fuse 10a
• A/c compressor clutch
• A/c compressor clutch relay (in underhood fuse/relay center)
• A/c compressor cycling switch (on top right of a/c accumulator)
• A/c ctrl
• A/c disable
• A/c high pressure cutout switch (on bottom rear of a/c compressor)
• A/c low pressure cutout switch (on top rear of a/c compressor)
• A/c maxi fuse 3 50a
• A/c req
• A/c switch
• Air temp dr sensor
• Aux fan ctrl
• Aux fan mini fuse 30a
• Auxiliary cooling fan motor
• Auxiliary cooling fan relay (exc 4.3l) (in underhood fuse/relay center)
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• Center
• Defogger element
• Diode
• Fan req
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G101 (right front of engine compartment)
• G119 (right front of engine)
• G120
• G120 (right side of engine)
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Hot in run or start
• Htr a/c fuse 12 25a
• Ign mini fuse 10a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Pnk
• Rear defogger system
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• Relay ctrl
• S110
• S128
• S146
• S147
• S147 (engine harn, near egr breakout)
• S180
• S185
• S186
• S244
• S268
• S298
• S308
• Tan
• Underhood fuse-relay
• Underhood fuse-relay center
• Valve ctrl
• Vehicle control module (left rear of engine compt)
• Water valve (suburban, utility, crew cab only) (right center of intake area)

Heater Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Heater Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harness)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 24 cm from i/p cluster breakout)
• (right side of engine)
• A/c maxi fuse 3 50a
• Air temp dr sensor
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• C10
• Defogger element
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G120
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Htr a/c fuse 12 25a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Rear defogger system
• Recirc ctrl
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• S110 (engine harness, near fuse-relay center)
• S147
• S243 (hvac harness, 4 cm from recirc door breakout)
• S244
• S268 (i/p harness, 6.5 cm from hvac connector breakout)
• S298
• Tan
• Underhood fuse-relay center

5.7L

5.7L (VIN R), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, near egr breakout)
• (engine harness, in fuse-relay center breakout)
• (engine harness, near fuse-relay center)
• (engine harness, near underhood lamp breakout)
• (exc 4.3 l)
• (fwd lamps harn, 5cm from right headlamp breakout)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 28 cm from cluster breakout)
• (i/p harness, in hvac connector breakout)
• (rear hvac control harness, 5 cm from hvac logic module breakout)
• (right side of engine)
• A/c comp mini fuse 10a
• A/c compressor clutch
• A/c compressor clutch relay (in underhood fuse/relay center)
• A/c compressor cycling switch (on top right of a/c accumulator)
• A/c ctrl
• A/c disable
• A/c high pressure cutout switch (on bottom rear of a/c compressor)
• A/c low pressure cutout switch (on top rear of a/c compressor)
• A/c maxi fuse 3 50a
• A/c req
• A/c switch
• Air temp dr sensor
• Aux fan ctrl
• Aux fan mini fuse 30a
• Auxiliary cooling fan motor
• Auxiliary cooling fan relay (exc 4.3l) (in underhood fuse/relay center)
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• Center
• Defogger element
• Diode
• Fan req
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G101 (right front of engine compartment)
• G119 (right front of engine)
• G120
• G120 (right side of engine)
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Hot in run or start
• Htr a/c fuse 12 25a
• Ign mini fuse 10a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Pnk
• Rear defogger system
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• Relay ctrl
• S110
• S128
• S146
• S147
• S147 (engine harn, near egr breakout)
• S180
• S185
• S186
• S244
• S268
• S298
• S308
• Tan
• Underhood fuse-relay
• Underhood fuse-relay center
• Valve ctrl
• Vehicle control module (left rear of engine compt)
• Water valve (suburban, utility, crew cab only) (right center of intake area)

Heater Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Heater Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harness)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 24 cm from i/p cluster breakout)
• (right side of engine)
• A/c maxi fuse 3 50a
• Air temp dr sensor
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• C10
• Defogger element
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G120
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Htr a/c fuse 12 25a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Rear defogger system
• Recirc ctrl
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• S110 (engine harness, near fuse-relay center)
• S147
• S243 (hvac harness, 4 cm from recirc door breakout)
• S244
• S268 (i/p harness, 6.5 cm from hvac connector breakout)
• S298
• Tan
• Underhood fuse-relay center

6.5L

6.5L (VIN F), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, 30cm from breakout to ebcm)
• (engine harn, near egr breakout)
• (engine harness, in fuse-relay center breakout)
• (engine harness, near fuse-relay center)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 28 cm from cluster breakout)
• (i/p harn, 8 cm from radio harness breakout)
• (i/p harness, in hvac connector breakout)
• (rear hvac control harness, 5 cm from hvac logic module breakout)
• (right side of engine)
• A/c comp mini fuse 10a
• A/c compressor clutch
• A/c compressor clutch relay (in underhood fuse/relay center)
• A/c compressor cycling switch (in low pressure line near compressor)
• A/c ctrl
• A/c disable
• A/c high pressure cutout switch (on a/c compressor)
• A/c low pressure cutout switch (on low pressure line)
• A/c maxi fuse 3 50a
• A/c req
• A/c switch
• Air temp dr sensor
• Aux fan ctrl
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• Center
• Defogger element
• Diode
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G120
• G120 (right side of engine)
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Hot in run or start
• Htr a/c fuse 12 25a
• Ign mini fuse 10a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Pnk
• Powertrain control module (left rear of engine compt)
• Rear defogger system
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• S107
• S110
• S146
• S147
• S147 (engine harn, near egr breakout)
• S185
• S186
• S212
• S244
• S268
• S298
• S308
• Tan
• Underhood fuse-relay
• Valve ctrl
• Water valve (suburban, utility, crew cab only) (right center of intake area)

6.5L (VIN S), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), A/C Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, 30cm from breakout to ebcm)
• (engine harn, near egr breakout)
• (engine harness, in fuse-relay center breakout)
• (engine harness, near fuse-relay center)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 28 cm from cluster breakout)
• (i/p harn, 8 cm from radio harness breakout)
• (i/p harness, in hvac connector breakout)
• (rear hvac control harness, 5 cm from hvac logic module breakout)
• (right side of engine)
• A/c comp mini fuse 10a
• A/c compressor clutch
• A/c compressor clutch relay (in underhood fuse/relay center)
• A/c compressor cycling switch (in low pressure line near compressor)
• A/c ctrl
• A/c disable
• A/c high pressure cutout switch (on a/c compressor)
• A/c low pressure cutout switch (on low pressure line)
• A/c maxi fuse 3 50a
• A/c req
• A/c switch
• Air temp dr sensor
• Aux fan ctrl
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• Center
• Defogger element
• Diode
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G120
• G120 (right side of engine)
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Hot in run or start
• Htr a/c fuse 12 25a
• Ign mini fuse 10a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Pnk
• Powertrain control module (left rear of engine compt)
• Rear defogger system
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• S107
• S110
• S146
• S147
• S147 (engine harn, near egr breakout)
• S185
• S186
• S212
• S244
• S268
• S298
• S308
• Tan
• Underhood fuse-relay
• Valve ctrl
• Water valve (suburban, utility, crew cab only) (right center of intake area)

Heater Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Heater Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harness)
• (hvac harness, 15cm from recirc door breakout)
• (i/p harn, 24 cm from i/p cluster breakout)
• (right side of engine)
• A/c maxi fuse 3 50a
• Air temp dr sensor
• Battery
• Blower motor
• Blower resistor (under right side of i/p, on heater housing)
• Blower switch
• C10
• Defogger element
• Front mode door motor (under i/p on heater- a/c case)
• Front temperature door motor (under i/p on heater- a/c case)
• Fuse block
• G120
• G202 (behind left side of i/p)
• Ground
• Heater and a/c control module
• High blower relay (under i/p on top of heater-a/c case)
• Hot at all times
• Hot in run
• Htr a/c fuse 12 25a
• Ignition
• Illumination
• Interior lights system
• Mode signal
• Off
• Rear defogger system
• Recirc ctrl
• Recirculation door motor (under i/p on heater- a/c case)
• Red
• S110 (engine harness, near fuse-relay center)
• S147
• S243 (hvac harness, 4 cm from recirc door breakout)
• S244
• S268 (i/p harness, 6.5 cm from hvac connector breakout)
• S298
• Tan
• Underhood fuse-relay center

ANTI-LOCK BRAKES

5.0L

5.0L (VIN M), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• (engine harn, 6.5 cm from underhood fuse relay center)
• (engine harn, near ebcm break- out)
• (engine harn, near tail- lamp breakout)
• (left side of i/p) data link connector
• (right lower front of engine)
• 4wd sw input
• 4wd telltale feed
• Abs ind
• Abs lamp control
• Abs maxi fuse 4 60a
• Brake fuse 18 10a
• Brake ind
• Brake lamp control
• Brake pressure warning switch
• Brake sw input
• Brake sw output
• Daytime running lamps module (left side of i/p)
• Diode 1 (underhood fuse/relay center)
• Ebcm ground
• Electronic brake control module (left front wheelhouse)
• G119
• Gauges fuse 4 10a
• Hot at all times
• Hot in run
• Hot in run, bulb test or start
• I/p fuse block
• Ign
• Instrument cluster
• Left front wheel speed sensor
• Lft frt sensor (+)
• Lft frt sensor (-)
• Nca
• Pnk
• Pump motor ground
• Pump motor power
• Red
• Right front wheel speed sensor
• Rt frt sensor (+)
• Rt frt sensor (-)
• S107
• S111
• S147
• S150
• S151
• S152
• S157
• S213
• Serial data line
• Tan
• Tcc/ stoplamp switch (top of brake pedal)
• Underhood fuse-relay center
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left side of transmission/ transfer case)
• Vehicle speed sig
• Vss (+)
• Vss (-)
• Vss sig

5.7L

5.7L (VIN R), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• (engine harn, 6.5 cm from underhood fuse relay center)
• (engine harn, near ebcm break- out)
• (engine harn, near tail- lamp breakout)
• (left side of i/p) data link connector
• (right lower front of engine)
• 4wd sw input
• 4wd telltale feed
• Abs ind
• Abs lamp control
• Abs maxi fuse 4 60a
• Brake fuse 18 10a
• Brake ind
• Brake lamp control
• Brake pressure warning switch
• Brake sw input
• Brake sw output
• Daytime running lamps module (left side of i/p)
• Diode 1 (underhood fuse/relay center)
• Ebcm ground
• Electronic brake control module (left front wheelhouse)
• G119
• Gauges fuse 4 10a
• Hot at all times
• Hot in run
• Hot in run, bulb test or start
• I/p fuse block
• Ign
• Instrument cluster
• Left front wheel speed sensor
• Lft frt sensor (+)
• Lft frt sensor (-)
• Nca
• Pnk
• Pump motor ground
• Pump motor power
• Red
• Right front wheel speed sensor
• Rt frt sensor (+)
• Rt frt sensor (-)
• S107
• S111
• S147
• S150
• S151
• S152
• S157
• S213
• Serial data line
• Tan
• Tcc/ stoplamp switch (top of brake pedal)
• Underhood fuse-relay center
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left side of transmission/ transfer case)
• Vehicle speed sig
• Vss (+)
• Vss (-)
• Vss sig

6.5L

6.5L (VIN F), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• (engine harn, 4 cm from i/p breakout)
• (engine harness, 13 cm in ebcm breakout)
• (left side of i/p) data link connector
• (top right rear of engine)
• 4wd input c2
• 4wd sw input
• A/t only
• Abs ind
• Abs lamp control
• Abs maxi fuse 4 60a
• Brake fuse 18 10a
• Brake ind
• Brake lamp control
• Brake pressure warning switch
• Brake sw input
• Daytime running lamps module (below left side of i/p)
• Diode 1 (underhood fuse/relay center)
• Ebcm ground
• Electronic brake control module (left front side of frame)
• G117
• Gauges fuse 4 10a
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• Ign
• Instrument cluster
• Left front wheel speed sensor
• Lft frt sensor (+)
• Lft frt sensor (-)
• Nca
• Pnk
• Powertrain control module (right side of i/p)
• Pump motor ground
• Pump motor power
• Red
• Right front wheel speed sensor
• Rt frt sensor (+)
• Rt frt sensor (-)
• S107
• S111 (engine harn, near ebcm breakout)
• S150
• S152
• S157
• S213
• Serial data line
• Serial data signal
• Tan
• Underhood fuse-relay center
• Vehicle speed sensor buffer (near steering column)
• Vss sig
• Vss sig out

6.5L (VIN S), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• (engine harn, 4 cm from i/p breakout)
• (engine harness, 13 cm in ebcm breakout)
• (left side of i/p) data link connector
• (top right rear of engine)
• 4wd input c2
• 4wd sw input
• A/t only
• Abs ind
• Abs lamp control
• Abs maxi fuse 4 60a
• Brake fuse 18 10a
• Brake ind
• Brake lamp control
• Brake pressure warning switch
• Brake sw input
• Daytime running lamps module (below left side of i/p)
• Diode 1 (underhood fuse/relay center)
• Ebcm ground
• Electronic brake control module (left front side of frame)
• G117
• Gauges fuse 4 10a
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• Ign
• Instrument cluster
• Left front wheel speed sensor
• Lft frt sensor (+)
• Lft frt sensor (-)
• Nca
• Pnk
• Powertrain control module (right side of i/p)
• Pump motor ground
• Pump motor power
• Red
• Right front wheel speed sensor
• Rt frt sensor (+)
• Rt frt sensor (-)
• S107
• S111 (engine harn, near ebcm breakout)
• S150
• S152
• S157
• S213
• Serial data line
• Serial data signal
• Tan
• Underhood fuse-relay center
• Vehicle speed sensor buffer (near steering column)
• Vss sig
• Vss sig out

7.4L

7.4L (VIN J), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Anti-lock Brake Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• (engine harn, 6.5 cm from underhood fuse relay center)
• (engine harn, near ebcm break- out)
• (engine harn, near tail- lamp breakout)
• (left side of i/p) data link connector
• (right lower front of engine)
• 4wd sw input
• 4wd telltale feed
• Abs ind
• Abs lamp control
• Abs maxi fuse 4 60a
• Brake fuse 18 10a
• Brake ind
• Brake lamp control
• Brake pressure warning switch
• Brake sw input
• Brake sw output
• Daytime running lamps module (left side of i/p)
• Diode 1 (underhood fuse/relay center)
• Ebcm ground
• Electronic brake control module (left front wheelhouse)
• G119
• Gauges fuse 4 10a
• Hot at all times
• Hot in run
• Hot in run, bulb test or start
• I/p fuse block
• Ign
• Instrument cluster
• Left front wheel speed sensor
• Lft frt sensor (+)
• Lft frt sensor (-)
• Nca
• Pnk
• Pump motor ground
• Pump motor power
• Red
• Right front wheel speed sensor
• Rt frt sensor (+)
• Rt frt sensor (-)
• S107
• S111
• S147
• S150
• S151
• S152
• S157
• S213
• Serial data line
• Tan
• Tcc/ stoplamp switch (top of brake pedal)
• Underhood fuse-relay center
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left side of transmission/ transfer case)
• Vehicle speed sig
• Vss (+)
• Vss (-)
• Vss sig

COMPUTER DATA LINES

Computer Data Lines for GMC Cab & Chassis K1997 3500

List of elements for Computer Data Lines for GMC Cab & Chassis K1997 3500:

• (behind left side of i/p)
• (gasoline) g134 (diesel) g120
• (gasoline-front top of engine, diesel-right top of cylinder head)
• 13 cm into ebcm breakout)
• Aux pwr fuse 7 25a
• Data clss
• Data clss 2
• Data link connector (left side of i/p)
• Diesel
• Dlc control
• Electronic brake control module (left front wheelhouse)
• G202
• Gasoline
• Hot at all times
• I/p fuse block
• Inflatable restraint sensing and diagnostic module (under driver's seat carpet)
• Power steering control module (center of i/p)
• Powertrain control module (right side of i/p)
• Prog enable
• Radio
• Remote control door lock receiver (behind center of i/p)
• S204
• S215
• S272
• S280 (i/p harness, approx 5 cm into dlc breakout)
• Serial data
• Tan
• Transfer case control module (steering column support bracket)
• Uart data
• Vehicle control module (engine compt, near ebcm)

COOLING FAN

5.0L

5.0L (VIN M), Cooling Fan Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Cooling Fan Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (fwd lamps harn, 5cm from right headlamp breakout)
• (i/p harness, 8 cm from radio breakout)
• (in underhood fuse/relay center)
• A/c comp mini fuse 10a
• Aux fan ctrl
• Aux fan mini fuse 30a
• Auxiliary cooling fan motor
• Auxiliary cooling fan relay
• Fan req
• G101 (right front of engine compartment)
• Heater and a/c control module
• Hot at all times
• Hot in run or start
• Recirculation door motor (under i/p on heater-a/c case)
• Red
• Relay ctrl
• S128
• S212
• Underhood fuse-relay center
• Vehicle control module (left rear of engine compt)

5.7L

5.7L (VIN R), Cooling Fan Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Cooling Fan Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (fwd lamps harn, 5cm from right headlamp breakout)
• (i/p harness, 8 cm from radio breakout)
• (in underhood fuse/relay center)
• A/c comp mini fuse 10a
• Aux fan ctrl
• Aux fan mini fuse 30a
• Auxiliary cooling fan motor
• Auxiliary cooling fan relay
• Fan req
• G101 (right front of engine compartment)
• Heater and a/c control module
• Hot at all times
• Hot in run or start
• Recirculation door motor (under i/p on heater-a/c case)
• Red
• Relay ctrl
• S128
• S212
• Underhood fuse-relay center
• Vehicle control module (left rear of engine compt)

CRUISE CONTROL

5.0L

5.0L (VIN M), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (i/p harn, 20 cm from cluster breakout)
• (i/p harn, 20 cm from heater/ a/c breakout)
• (i/p harn, left rear of engine compt)
• (i/p harness, 6 cm from steering column harness breakout)
• 4000 pulses/mile
• A/t
• A12
• A13
• A14
• A15
• Brake fuse 18 10a
• Clutch pedal switch (top of clutch pedal)
• Cruise control module (front of engine compt near left fender)
• Cruise control switch
• Cruise fuse 6 10a
• Cruise on input
• Cruise status
• Disengage input
• G120 (right side of engine)
• Ground
• Hot at all times
• Hot in run
• I/p fuse block
• Ignition
• M/t
• Off
• R/a
• Resume/accel input
• S/c
• S153
• S215
• S220
• S221
• S222
• S299
• Set/coast input
• Stop/haz fuse 1 20a
• Tcc/stoplamp brake switch (top of brake pedal)
• Vehicle control module (vcm) (in engine compt, on left fender)
• Vehicle speed input
• Vehicle speed sensor (vss) (left side of transmission)
• Vss return
• Vss signal

5.7L

5.7L (VIN R), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (i/p harn, 20 cm from cluster breakout)
• (i/p harn, 20 cm from heater/ a/c breakout)
• (i/p harn, left rear of engine compt)
• (i/p harness, 6 cm from steering column harness breakout)
• 4000 pulses/mile
• A/t
• A12
• A13
• A14
• A15
• Brake fuse 18 10a
• Clutch pedal switch (top of clutch pedal)
• Cruise control module (front of engine compt near left fender)
• Cruise control switch
• Cruise fuse 6 10a
• Cruise on input
• Cruise status
• Disengage input
• G120 (right side of engine)
• Ground
• Hot at all times
• Hot in run
• I/p fuse block
• Ignition
• M/t
• Off
• R/a
• Resume/accel input
• S/c
• S153
• S215
• S220
• S221
• S222
• S299
• Set/coast input
• Stop/haz fuse 1 20a
• Tcc/stoplamp brake switch (top of brake pedal)
• Vehicle control module (vcm) (in engine compt, on left fender)
• Vehicle speed input
• Vehicle speed sensor (vss) (left side of transmission)
• Vss return
• Vss signal

6.5L

6.5L (VIN F), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, 4 cm from i/p harness breakout)
• (i/p harn, 12 cm from steering column breakout)
• (i/p harn, 6 cm from steering column breakout)
• A/t
• A12
• A13
• A14
• A15
• Brake fuse 18 10a
• Clutch pedal switch (top of clutch pedal)
• Cruise fuse 6 10a
• Cruise on input
• D11
• D15
• Disengage input
• Fuse block
• Hot at all times
• Hot in run
• M/t
• Multifunction lever
• Off
• Powertrain control module (pcm) (behind center of i/p)
• R/a
• Resume/accel input
• S/c
• S220
• S299
• Set/coast input
• Stop/haz fuse 1 20a
• Tcc/stoplamp switch (top of brake pedal)
• Vehicle speed sensor (vss) (left side of transmission)
• Vss return

6.5L (VIN S), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (engine harn, 4 cm from i/p harness breakout)
• (i/p harn, 12 cm from steering column breakout)
• (i/p harn, 6 cm from steering column breakout)
• A/t
• A12
• A13
• A14
• A15
• Brake fuse 18 10a
• Clutch pedal switch (top of clutch pedal)
• Cruise fuse 6 10a
• Cruise on input
• D11
• D15
• Disengage input
• Fuse block
• Hot at all times
• Hot in run
• M/t
• Multifunction lever
• Off
• Powertrain control module (pcm) (behind center of i/p)
• R/a
• Resume/accel input
• S/c
• S220
• S299
• Set/coast input
• Stop/haz fuse 1 20a
• Tcc/stoplamp switch (top of brake pedal)
• Vehicle speed sensor (vss) (left side of transmission)
• Vss return

7.4L

7.4L (VIN J), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Cruise Control Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (i/p harn, 20 cm from cluster breakout)
• (i/p harn, 20 cm from heater/ a/c breakout)
• (i/p harn, left rear of engine compt)
• (i/p harness, 6 cm from steering column harness breakout)
• 4000 pulses/mile
• A/t
• A12
• A13
• A14
• A15
• Brake fuse 18 10a
• Clutch pedal switch (top of clutch pedal)
• Cruise control module (front of engine compt near left fender)
• Cruise control switch
• Cruise fuse 6 10a
• Cruise on input
• Cruise status
• Disengage input
• G120 (right side of engine)
• Ground
• Hot at all times
• Hot in run
• I/p fuse block
• Ignition
• M/t
• Off
• R/a
• Resume/accel input
• S/c
• S153
• S215
• S220
• S221
• S222
• S299
• Set/coast input
• Stop/haz fuse 1 20a
• Tcc/stoplamp brake switch (top of brake pedal)
• Vehicle control module (vcm) (in engine compt, on left fender)
• Vehicle speed input
• Vehicle speed sensor (vss) (left side of transmission)
• Vss return
• Vss signal

DEFOGGERS

Defogger Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Defogger Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (left side of i/p) convenience center
• C222
• G202 (behind left side of i/p)
• G305 (right "b" pillar)
• Hot in run
• Hot in run or start
• Htr-a/c fuse 12 25a
• Hvac control module
• I/p fuse block
• Left cargo door contactor
• Left rear cargo door defogger grid
• Pick-up w/ extended or crew cab
• Rear defogger switch
• Rear window defogger grid
• Right cargo door contactor
• Right rear cargo door defogger grid
• Rr-defog mini fuse 30a
• S218
• S268
• S410
• Solid state time delay relay
• Suburban/utility w/ liftgate
• Suburban/utility w/o liftgate
• Underhood fuse/relay center

ELECTRONIC POWER STEERING

Electronic Power Steering Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Electronic Power Steering Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (under left side of i/p) data link connector (dlc)
• 5 volt ref
• Battery feed
• Computer data lines system
• Electronic variable orifice (evo) solenoid (on steering pump)
• Evo sol feed
• Evo sol output
• G134 (front top of engine)
• Gauges fuse 4 10a
• Ground
• Hot at all times
• Hot in run or start
• I/p fuse block
• Ignition
• Pnk
• Pos sig out
• Position signal
• Power steering control module (pscm) (under center of i/p)
• S210 (i/p harn, approx 5 cm into data link connector breakout)
• S213
• S215
• S221 (i/p harn, gas: approx 20 cm from i/p cluster breakout; diesel: approx 5 cm into power steering control module breakokut)
• Security fuse 21 20a
• Sen rtn
• Sensor return
• Srl data class 13
• Steering wheel position sensor (on steering column)
• Vehicle control module (vcm) (in engine compt)
• Volt ref
• Vss out
• Vss signal input

ENGINE PERFORMANCE

5.0L

5.0L (VIN M), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500:

• (attached to right rear of throttle body) idle air control (iac) valve
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Shift sol. ctrl
• Tan
• Tcc sol ctrl
• Tcc sol. ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

5.0L (VIN M), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500:

• (w/4l60-e trans.)
• (w/4l80-e trans.)
• 1-2 shift solenoid
• 2-3 shift solenoid
• 3-2 shift solenoid
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• Hot in run & start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk tan
• Pressure control solenoid valve
• Red
• S104
• S108
• S161
• Tan
• Tcc solenoid
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center
• W/4l60e 4-speed trans. only

5.0L (VIN M), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

5.0L (VIN M), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out

5.7L

5.7L (VIN R), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500:

• (attached to right rear of throttle body) idle air control (iac) valve
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Shift sol. ctrl
• Tan
• Tcc sol ctrl
• Tcc sol. ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

5.7L (VIN R), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500:

• (w/4l60-e trans.)
• (w/4l80-e trans.)
• 1-2 shift solenoid
• 2-3 shift solenoid
• 3-2 shift solenoid
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• Hot in run & start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk tan
• Pressure control solenoid valve
• Red
• S104
• S108
• S161
• Tan
• Tcc solenoid
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center
• W/4l60e 4-speed trans. only

5.7L (VIN R), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

5.7L (VIN R), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out

6.5L

6.5L (VIN F), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 43 cm from breakout to ebcm)
• (engine harness, approx 8 cm from fuel heater breakout)
• (engine jumper harness)
• (engine sensor harness)
• (front engine cover) crankshaft position (ckp) sensor)
• (front of engine)
• (i/p harness, approx 16 cm into i/p cluster breakout)
• (left lower front of engine) engine coolant temperature (ect) sensor
• (right top of cylinder head) g119
• 12v
• 3/2 shift sol.
• 4wd signal
• 5 volt ref
• 5 vref
• 5v ref volt
• A/c request sig
• A/c system
• A/t fluid pressure (tfp) manual valve position switch
• A10
• A11 3 mode cruise a12
• Anti-lock brakes system
• App 1 sig
• App 2 sig
• App 3 sig
• Automatic transmission input shaft speed (a/t iss) sensor (left side of transmission near front)
• B10
• B11
• B12
• Baro sensor input
• Boost pressure sensor
• Brake sw in
• Brake switch input
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Cam posit sens sig rtn
• Camshaft posit sens
• Closure gnd
• Cruise control
• Cruise ctrl sw engage
• Cruise eng sw retard
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Ect temp sens in
• Engine crank sens input
• Exhaust gas recirculation (egr) control/ barometric (baro) pressure sensor (right of steering column)
• Force mtr hi
• Force mtr low
• Fuel pump input
• Fuel pump rly ctrl
• Fuel sol closure (5v sig)
• Fuel temp sens (5v sig)
• Glow plug "wait" lp out
• Glow plug relay
• Ground
• Heavy duty electronic 4-spd automatic overdrive transmission
• Intake air temperature (iat) sensor
• Intake man air temp sens
• Map sens input
• Nca
• On/off
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Pressure control solenoid valve
• Radio
• Range mode sel a
• Range mode sel b
• Range mode sel c
• Red
• Resume
• S140
• S170
• S199
• S211
• S215
• S230
• Sensor gnd
• Set
• Shift sol. a
• Shift sol. b
• Switch
• Tan
• Timing stepper mtr (high)
• Timing stepper mtr (low)
• Transmission speed input
• Transmission temp input
• Transmission temperature sensor
• Transmissions system
• Vehicle speed input
• Vehicle speed sensor (on transmission, left rear side)
• Vehicle speed sensor buffer (below left side of i/p)
• Vss hi
• Vss output
• Vss rtn
• Vss sig

6.5L (VIN F), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 4 cm from i/p harness breakout)
• (engine jumper harness, toward fuel temperature sensor)
• 5 volt ref
• Accelerator pedal position (app) module (below i/p, attached to accelerator bracket)
• Brake switch assembly (at rear of brake pedal support bracket)
• Clutch pedal position (cpp) switch (m/t only) (top of clutch pedal)
• Cmp sig
• D2 trans fuse 20 20a e1
• D8 stop/haz fuse 1 20a c7
• Ecm h7
• Electronic brake control module (left frame rail, near center of vehicle)
• Engine shutoff solenoid
• Fuel f5
• Fuel solenoid
• Fuel solenoid driver
• Fuel temperature sensor
• Fuse 20a
• High res sig
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• M4 brake fuse 18 10a n3
• Pnk
• Pnk pnk
• Power distribution system
• Red
• S190
• S198
• S220 (i/p harness, approx 6 cm from steering column breakout)
• S222 (m/t) s152 (a/t)
• S299
• Sens grd
• Sol fuse 20a
• Tan d
• Timing stepper motor (top front of engine)
• Underhood fuse-relay center

6.5L (VIN F), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 37 cm from breakout to fuel relay center) s100
• (left frame rail, below driver's door)
• (right top of cylinder head)
• (right top of cylinder head) g119
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Ecm-b fuse 20a
• F11
• Fuel lift pump
• Fuel pump prime connector
• Fuel pump relay (in underhood fuse-relay center)
• Fuel pump/ oil pressure switch and sender (left rear of engine)
• G119
• G12
• Gauges fuse 4 10a
• Hot at all times
• Hot in run or start
• I/p fuse block
• Instrument cluster
• Instrument cluster system
• Instrument cluster system (fuel pump balance relay)
• Pnk
• Red
• S101
• S103
• S147
• S213
• S318
• Service engine soon indicator
• Service throttle soon indicator
• Tan
• Underhood fuse-relay center
• Vehicle speed input
• W/dual tanks
• W/o dual tanks
• Wait to start "glow plugs" indicator
• Water in fuel indicator
• Water in-fuel sensor

6.5L (VIN F), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500:

• "serv eng soon" ind
• "serv throttle soon" ind
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 13 cm into generator breakout)
• (engine harness, approx 34 cm from bulkhead to inside of pass compt)
• (engine harness, approx 64 cm from glow plug controller)
• (engine jumper harness, from fuel solenoid driver)
• (left side of i/p)
• (right top of cylinder head) g119
• 12v battery (fused)
• 12v battery fused
• 3/2 ctrl out
• A/c enable
• A/c system
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (dlc)
• Egr sol output
• Egr valve sol putput
• Electronic brake brake control module (ebcm) (at left front wheelhouse)
• Eng-i k7
• Engine shutoff sol out
• Exhaust gas recirculation (egr) vent solenoid
• Exhaust gas recirculation egr solenoid (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel sol module (5 vref)
• Fuel sol module feed
• Fuse 10a
• Fuse 20a
• Fusible link
• Fusible links
• G119 (right top of cylinder head)
• Glow plug 1
• Glow plug 2
• Glow plug 3
• Glow plug 4
• Glow plug 5
• Glow plug 6
• Glow plug 7
• Glow plug 8
• Glow plug output
• Glow plug relay (left rear of engine near bulkhead)
• Glow plugs g4
• Grd
• Ground
• Hot at all times
• Hot in run or start
• Ign
• Ignition
• Maf
• Mass air flow (maf) sensor
• Pcm gnd
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Red
• Relay ctrl
• S103
• S108
• S137
• S138
• S147
• S150
• S191
• S269
• Serial data sig
• Shift sol a input
• Shift sol b input
• Signal
• Tan
• Tps no.2 ref voltage
• Underhood fuse-relay center
• Wait to start ind
• Wastegate sol
• Wastegate solenoid

6.5L (VIN S), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 43 cm from breakout to ebcm)
• (engine harness, approx 8 cm from fuel heater breakout)
• (engine jumper harness)
• (engine sensor harness)
• (front engine cover) crankshaft position (ckp) sensor)
• (front of engine)
• (i/p harness, approx 16 cm into i/p cluster breakout)
• (left lower front of engine) engine coolant temperature (ect) sensor
• (right top of cylinder head) g119
• 12v
• 3/2 shift sol.
• 4wd signal
• 5 volt ref
• 5 vref
• 5v ref volt
• A/c request sig
• A/c system
• A/t fluid pressure (tfp) manual valve position switch
• A10
• A11 3 mode cruise a12
• Anti-lock brakes system
• App 1 sig
• App 2 sig
• App 3 sig
• Automatic transmission input shaft speed (a/t iss) sensor (left side of transmission near front)
• B10
• B11
• B12
• Baro sensor input
• Boost pressure sensor
• Brake sw in
• Brake switch input
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Cam posit sens sig rtn
• Camshaft posit sens
• Closure gnd
• Cruise control
• Cruise ctrl sw engage
• Cruise eng sw retard
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Ect temp sens in
• Engine crank sens input
• Exhaust gas recirculation (egr) control/ barometric (baro) pressure sensor (right of steering column)
• Force mtr hi
• Force mtr low
• Fuel pump input
• Fuel pump rly ctrl
• Fuel sol closure (5v sig)
• Fuel temp sens (5v sig)
• Glow plug "wait" lp out
• Glow plug relay
• Ground
• Heavy duty electronic 4-spd automatic overdrive transmission
• Intake air temperature (iat) sensor
• Intake man air temp sens
• Map sens input
• Nca
• On/off
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Pressure control solenoid valve
• Radio
• Range mode sel a
• Range mode sel b
• Range mode sel c
• Red
• Resume
• S140
• S170
• S199
• S211
• S215
• S230
• Sensor gnd
• Set
• Shift sol. a
• Shift sol. b
• Switch
• Tan
• Timing stepper mtr (high)
• Timing stepper mtr (low)
• Transmission speed input
• Transmission temp input
• Transmission temperature sensor
• Transmissions system
• Vehicle speed input
• Vehicle speed sensor (on transmission, left rear side)
• Vehicle speed sensor buffer (below left side of i/p)
• Vss hi
• Vss output
• Vss rtn
• Vss sig

6.5L (VIN S), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 4 cm from i/p harness breakout)
• (engine jumper harness, toward fuel temperature sensor)
• 5 volt ref
• Accelerator pedal position (app) module (below i/p, attached to accelerator bracket)
• Brake switch assembly (at rear of brake pedal support bracket)
• Clutch pedal position (cpp) switch (m/t only) (top of clutch pedal)
• Cmp sig
• D2 trans fuse 20 20a e1
• D8 stop/haz fuse 1 20a c7
• Ecm h7
• Electronic brake control module (left frame rail, near center of vehicle)
• Engine shutoff solenoid
• Fuel f5
• Fuel solenoid
• Fuel solenoid driver
• Fuel temperature sensor
• Fuse 20a
• High res sig
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• M4 brake fuse 18 10a n3
• Pnk
• Pnk pnk
• Power distribution system
• Red
• S190
• S198
• S220 (i/p harness, approx 6 cm from steering column breakout)
• S222 (m/t) s152 (a/t)
• S299
• Sens grd
• Sol fuse 20a
• Tan d
• Timing stepper motor (top front of engine)
• Underhood fuse-relay center

6.5L (VIN S), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 37 cm from breakout to fuel relay center) s100
• (left frame rail, below driver's door)
• (right top of cylinder head)
• (right top of cylinder head) g119
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Ecm-b fuse 20a
• F11
• Fuel lift pump
• Fuel pump prime connector
• Fuel pump relay (in underhood fuse-relay center)
• Fuel pump/ oil pressure switch and sender (left rear of engine)
• G119
• G12
• Gauges fuse 4 10a
• Hot at all times
• Hot in run or start
• I/p fuse block
• Instrument cluster
• Instrument cluster system
• Instrument cluster system (fuel pump balance relay)
• Pnk
• Red
• S101
• S103
• S147
• S213
• S318
• Service engine soon indicator
• Service throttle soon indicator
• Tan
• Underhood fuse-relay center
• Vehicle speed input
• W/dual tanks
• W/o dual tanks
• Wait to start "glow plugs" indicator
• Water in fuel indicator
• Water in-fuel sensor

6.5L (VIN S), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500:

• "serv eng soon" ind
• "serv throttle soon" ind
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 13 cm into generator breakout)
• (engine harness, approx 34 cm from bulkhead to inside of pass compt)
• (engine harness, approx 64 cm from glow plug controller)
• (engine jumper harness, from fuel solenoid driver)
• (left side of i/p)
• (right top of cylinder head) g119
• 12v battery (fused)
• 12v battery fused
• 3/2 ctrl out
• A/c enable
• A/c system
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (dlc)
• Egr sol output
• Egr valve sol putput
• Electronic brake brake control module (ebcm) (at left front wheelhouse)
• Eng-i k7
• Engine shutoff sol out
• Exhaust gas recirculation (egr) vent solenoid
• Exhaust gas recirculation egr solenoid (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel sol module (5 vref)
• Fuel sol module feed
• Fuse 10a
• Fuse 20a
• Fusible link
• Fusible links
• G119 (right top of cylinder head)
• Glow plug 1
• Glow plug 2
• Glow plug 3
• Glow plug 4
• Glow plug 5
• Glow plug 6
• Glow plug 7
• Glow plug 8
• Glow plug output
• Glow plug relay (left rear of engine near bulkhead)
• Glow plugs g4
• Grd
• Ground
• Hot at all times
• Hot in run or start
• Ign
• Ignition
• Maf
• Mass air flow (maf) sensor
• Pcm gnd
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Red
• Relay ctrl
• S103
• S108
• S137
• S138
• S147
• S150
• S191
• S269
• Serial data sig
• Shift sol a input
• Shift sol b input
• Signal
• Tan
• Tps no.2 ref voltage
• Underhood fuse-relay center
• Wait to start ind
• Wastegate sol
• Wastegate solenoid

7.4L

7.4L (VIN J), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis K1997 3500:

• (attached to right rear of throttle body) idle air control (iac) valve
• (engine harness, approx 11 cm into egr valve breakout)
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Air pump relay ctrl
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Knock sensor (right side of engine block)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Pnk pnk pnk pnk pnk pnk pnk
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S145
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Tan
• Tcc sol ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

7.4L (VIN J), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis K1997 3500:

• 1-2 shift solenoid
• 2-3 shift solenoid
• Air injection reaction (a.i.r.) pump clutch (front of air injection pump, front of engine)
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• G119 (right front of engine block)
• Hot in run or start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk pnk pnk pnk
• Pnk pnk pnk tan pnk pnk
• Pressure control solenoid valve
• Red
• S104
• S108
• S147
• S154
• S155
• Secondary air injection reaction (a.i.r.) pump relay (underhood fuse/ relay center)
• Tan
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center

7.4L (VIN J), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan pnk pnk
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S146
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/california emissions
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

7.4L (VIN J), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis K1997 3500:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out

EXTERIOR LIGHTS

Back-up Lamps Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Back-up Lamps Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (left side of trans) backup lamp switch
• A/t
• Backup lamps signal (trailer tow package) (wire cut and taped to harness)
• C218
• Convenience center (under left side of dash)
• G415 (left frame rail, behind bumper)
• Hot in run, bulb test or start
• I/p fuse block
• Left backup lamp
• M/t
• Mirrors system
• Park/neutral position switch (left top of trans)
• Pnk
• Right backup lamp
• S411
• S414
• Turn b/u fuse 16 20a

Exterior Lamps Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Exterior Lamps Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (forward lamps harn, 7cm from left headlamp breakout) s122
• (forward lamps harness, 5cm from right headlamp breakout) s122
• (frame ground: on rear of vehicle)
• (front to rear body harness, near chmsl harness breakout)
• (i/p harness, 12 cm from steering column breakout) s210
• (i/p harness, 4cm into i/p cluster breakout) s267
• (i/p harness, 8cm into i/p cluster breakout) s214
• (license lamp harness, 15cm from left license lamp toward taillamp breakout) s415
• (rear lamps harn, 28cm from trailer harness breakout) (w/ trailer pkg) s413
• (rear lamps harness, near taillamps extension harness break- out) s412
• Auxiliary lead (taped to harness)
• Backup lights circuit
• C219
• C220
• Cab clearance lamps
• Cargo lamp
• Cargo lamp switch
• Center high mount stop lamp
• Ch- msl lp
• Column harness breakout)
• Convenience center (under left side of dash)
• Cr lp
• Cruise control system
• Ctsy fuse 20a
• Fuse block
• G108 (left radiator support, near left headlamp)
• G120 (gas: right front of engine block; diesel: right top of cylinder head)
• G1o1 (right inner fender, below underhood reel lamp)
• G202 (behind left side of dash)
• G202 (behind left side of i/p)
• G305 (right "b" pillar)
• G415 (left frame rail, behind bumper)
• H9 turn pwr h8 haz pwr h7 flshr out g8 gnd
• Hazard
• Headlamp & panel dimmer switch
• Headlights system
• Hot at all times
• Hot in run, bulb test or start
• I/p fuse block
• Instru- ment cluster
• Interior lights system
• Left
• Left front marker lamp
• Left front park/ turn lamps
• Left tail/ stop/ turn lamp
• Left turn indic
• License lamp
• License lamps
• Maxi fuse 30a
• Nca
• Normal
• Off
• Park
• Park lps fuse 9 20a
• Pickup
• Platform hitch ground
• Pnk
• Rear clearance lamps circuit
• Red
• Rheo- stat
• Right
• Right front marker lamp
• Right front park/ turn lamps
• Right tail/ stop/ turn lamp
• Right turn indic
• S107
• S119 (forward lamps harn, 20cm from washer pump breakout)
• S123
• S128
• S204
• S215
• S242
• S251
• S299
• S316
• S411
• S416
• S419
• S421 (rear lamp harness, 7cm from license lamp breakout)
• S422 (rear lamp harn, 7cm from trailer harness breakout)
• S424
• Stop- lamp relay (except subur- ban/ utility)
• Stop/ haz fuse 1 15a
• Suburban/ utility
• Tcc/ stop lamp switch (top of brake pedal)
• Trailer towing adapter (wires are cut and taped to harness)
• Turn- b/u fuse 16 15a
• Turn/ hazard switch
• Turn/hazard flasher (convenience center: under left side of dash)
• Under- hood fuse relay center (left rear of engine compt.)
• Under- hood fuse- relay center (left rear of engine compt.)
• W/ dual rear wheels
• W/ step bumper
• W/o step bumper

GROUND DISTRIBUTION

Ground Distribution Wiring Diagram (1 of 5) for GMC Cab & Chassis K1997 3500

List of elements for Ground Distribution Wiring Diagram (1 of 5) for GMC Cab & Chassis K1997 3500:

• (i/p harness, approx 24 cm from instrument cluster breakout)
• (left front of intake manifold)
• (right front of engine)
• A16
• Ashtray lamp
• Audio alarm module
• Auxiliary cooling fan motor
• Auxiliary fan control switch
• Btsi ground
• C10
• Cargo lamp switch (pickup)
• Cigar lighter
• Convenience center
• D10
• D12
• D13
• Data link connector
• Daytime running lamps module
• Fog lamp switch
• From convenience center (diagram 3 of 4)
• Front windshield wiper/ washer pump motor
• G101 (right front wheelhouse)
• G101 (right inner fender, below underhood reel lamp)
• G105 (right rear of engine compt)
• G108 (left radiator support, near left headlamp)
• G110 (diesel)
• G117 (right rear of engine)
• G119 (gasoline)
• G202 (behind left side of i/p)
• Headlamp and panel dimmer switch
• Heater and a/c control switch
• Hvac control module
• I/p compartment lamp
• Ignition switch ground
• Inflatable restraint i/p module enable switch
• Left battery
• Left fog lamp
• Left front door jamb switch
• Left front park/ turn lamp
• Left high beam headlamp
• Left high/ low beam headlamp
• Left horn
• Left low beam headlamp
• Low coolant level indicator module
• Power outlet
• Radio
• Rear liftgate release switch (suburban/ utility)
• Rear window washer pump motor
• Rear window wiper/ washer switch
• Rear window wiper/ washer switch (suburban/ utility)
• Right fog lamp
• Right front door jamb switch
• Right front park/ turn lamp
• Right high beam headlamp
• Right high/ low beam headlamp
• Right horn
• Right low beam headlamp
• S123 (forward lamps harness, approx 20 cm from left park/lamp breakout)
• S128 (forward lamps harness, approx 5 cm from right headlamp breakout)
• S158 (in washer pump jumper harness)
• S204 (i/p harness, approx 8 cm from dlc harness breakout)
• S218 (i/p harness, aprrox 16 cm from radio harness breakout)
• S298
• Spare
• Steering column ground
• Transfer case control module
• Transfer case select switch
• Turn/ hazard flasher
• Uncoated
• W/ dual horns
• W/ v22 (quad headlamps)
• Windshield wiper motor module

Ground Distribution Wiring Diagram (2 of 5) for GMC Cab & Chassis K1997 3500

List of elements for Ground Distribution Wiring Diagram (2 of 5) for GMC Cab & Chassis K1997 3500:

• (4wd harness, approx 10 cm from transfer case relay breakout)
• (engine harness, 8-16 cm from a/c compressor clutch connector)
• (engine harness, approx 16 cm into vehicle speed sensor breakout)
• (i/p harness, approx 8 cm from i/p cluster breakout)
• (not used)
• (oxygen sensor jumper harness, approx 22 cm into harness)
• (right front of engine block)
• 4.3l
• A/c compressor clutch
• A/c compressor clutch relay
• A/c compressor cycling switch
• A/c high pressure cutout switch
• Air reaction injection (secondary) pump (7.4l only)
• Balance fuel gage sender
• Blower motor
• Brake pressure warning switch
• Cruise control module
• Data link connector
• Electronic brake control module
• Evaporative emissions purge vacuum solenoid switch
• Except 4.3l
• Front axle actuator
• Front mode door motor
• Front temperature door motor
• Fuel pump and sender
• Fuel pump balance module
• Fuel pump relay
• G120
• G131 (near thermostat housing)
• G134 (front top of engine)
• Gasoline
• Heated oxygen sensor bank 1 sensor 1
• Heated oxygen sensor bank 1 sensor 2
• Heated oxygen sensor bank 2 sensor 1
• Heated oxygen sensor bank 2 sensor 2
• High a/c pressure cutout switch
• High blower motor relay
• Ignition coil module
• Instrument cluster
• Mass airflow sensor
• Park/ neutral position switch
• Power steering control module
• Recirculation door motor
• S103 (vin j-engine harness, approx 12 cm from fuel injector breakout, except vin j-engine harness, approx 11 cm from breakout to egr valve)
• S107 (vin j-engine harness, approx 18 cm from fuse-relay center breakout, except vin j-engine harness, 25-35 cm from breakout to egr valve)
• S147 (vin j-engine harness, approx 5 cm from fuel injector breakout, except vin j-engine harness, approx 6 cm from egr breakout)
• S149
• S156
• S162 (except vin j-engine harness, approx 17 cm from starter solenoid breakout, vin j-engine harness, approx 41 cm from left oxygen sensor breakout)
• S180 (engine harness, approx 21-36 cm from under hood lamp breakout)
• S185
• S186
• S215
• S244 (hvac harness, approx 15 cm from recirculation door breakout)
• S302
• S317 (taillamp extension harness, approx 10 cm from fuel pump and sender breakout)
• Starter relay
• Stoplamp relay
• Transfer case relay
• Under- hood lamp
• Under- hood reel lamp
• Underhood fuse- relay center
• Vehicle control module
• W/ dual tanks
• W/o dual tanks (except 4.3l)
• Water valve

Ground Distribution Wiring Diagram (3 of 5) for GMC Cab & Chassis K1997 3500

List of elements for Ground Distribution Wiring Diagram (3 of 5) for GMC Cab & Chassis K1997 3500:

• (crossbody harness, approx 6 cm into seat belt switch breakout)
• (i/p harness, approx 8 cm from i/p cluster breakout)
• (inside left front door harness, near tweeter)
• (power lumbar seat jumper, approx 20 cm from right power seat breakout)
• 4.3l only
• Balance fuel gage sender
• Bench seat
• C210
• C220
• Center high mount stop- lamp
• Convenience center
• Convenience center (under left side of i/p)
• Data link connector
• Diesel
• Door lock relay
• Electrochromic rearview mirror w/ compass
• Four-wheel drive indicator lamp
• Fuel gage sender
• Fuel pump and sender
• Fuel pump balance module
• Fuel pump relay
• G120 (right top of cylinder head)
• G416 (inside left framerail, near rear crossmember)
• Instrument cluster
• Interior lamp control module
• Left clearance lamp
• Left front power window lock switch
• Left illuminated vanity mirror
• Left power lumbar support motor
• Left rear power window switch
• Mass airflow sensor
• Others
• Power amplifier
• Power amplifier relay
• Power lumbar motor
• Power outside rearview mirror switch
• Power steering control module
• Powertrain control module
• Rear window lockout switch
• Remote control door lock receiver
• Right clearance lamp
• Right front power window switch
• Right illuminated vanity mirror
• Right power left power seat
• Right power lumbar support motor
• Right rear power window switch
• Roof marker lamps
• S103 (engine harness, approx 11 cm from breakout to right side glow plugs)
• S215
• S251 (crossbody harness, approx 12 cm right of left door harness breakout)
• S259
• S303
• S316 (vanity mirror jumper harness, approx 10 cm toward left illuminated vanity mirror)
• S317 (taillamp extension harness, approx 10 cm from fuel gage sender breakout)
• S500
• Seat belt switch
• To g202 (diagram 1 of 4)
• Transfer case mode selector illumination lamp
• Under- hood fuse- relay center
• Vehicle speed sensor buffer

Ground Distribution Wiring Diagram (4 of 5) for GMC Cab & Chassis K1997 3500

List of elements for Ground Distribution Wiring Diagram (4 of 5) for GMC Cab & Chassis K1997 3500:

• (license lamps harness, approx 4 cm from tail- lamp harness breakout)
• (rear heat and a/c harness, 7 cm from blower motor resistor breakout)
• (rear lamps harness, 17-33 cm from taillamps extension breakout)
• Auxiliary heater- a/c logic module
• Balance fuel pump
• Center high mount stoplamp
• Chassis cab & heavy duty
• Door contact button
• Door lock control module
• Endgate marker lamps
• Except chassis cab & heavy duty
• Front auxiliary heater-a/c control module
• Front dome lamp
• Fuel lift pump
• G202 (left side of i/p)
• G305 (right 'b' pillar)
• G415 (frame ground, rear of vehicle)
• G415 (left frame rail, behind bumper)
• G416 (left frame rail, near rear crossmember)
• Inflatable restraint front end sensor
• Inflatable restraint sensing and diagnostic module
• Left cargo door defogger grid
• Left front clearance lamp
• Left license lamp
• Left rear clearance lamp
• Left rear fender
• Left rear tail, stop, license, turn & backup lamps
• Left rear tail, stop, turn & backup lamps
• Left tail, stop, turn & backup lamps
• Overhead console lamps
• Pickup w/ dual rear wheels
• Rear auxiliary heater-a/c control module
• Rear auxiliary mode door motor
• Rear auxiliary temp door motor
• Rear blower motor
• Rear dome lamp
• Rear liftgate window defogger grid
• Rear wiper motor module
• Right cargo door defogger grid
• Right front clearance lamp
• Right license lamp
• Right rear clearance lamp
• Right rear door jamb switch
• Right rear fender
• Right rear tail, stop, license, turn & backup lamps
• Right rear tail, stop, turn & backup lamps
• Right tail, stop, turn & backup lamps
• S307 (rear hvac control harness, approx 10 cm from hvac logic module breakout)
• S319 (taillamp extension harness, approx 10 cm from fuel pump and sender breakout (fuel gage sender breakout-diesel))
• S403
• S410 (utility-front to rear lamps harness, 12-22 cm from right rear door speaker breakout, suburban-front to rear body harness, 12-22 cm from right rear door speaker breakout)
• S411
• S411 (rear lamps harness, 17-33 cm from taillamps extension breakout)
• S416
• Suburban & utility
• Trailer ground (taped back)
• Utility only
• W/ dual tanks

Ground Distribution Wiring Diagram (5 of 5) for GMC Cab & Chassis K1997 3500

List of elements for Ground Distribution Wiring Diagram (5 of 5) for GMC Cab & Chassis K1997 3500:

• (engine harness, 28 cm from a/c compressor clutch connector)
• (right top of cylinder head)
• A/c compressor clutch
• A/c compressor clutch relay
• A/c low pressure switch
• Blower motor
• Brake pressure warning switch
• Diesel
• Electronic brake control module
• Front axle actuator
• Front mode door motor
• Front temperature door motor
• Fuel heater
• G117
• Glow plug relay
• High blower motor relay
• Low coolant level sensor
• Park/ neutral position switch
• Recirculation door motor
• S107 (engine harness, approx 30 cm from breakout to ebcm)
• S147 (engine harness, approx 4 cm from breakout to right side glow plugs)
• S185
• S186
• S244 (hvac harness, approx 15 cm from recirculation door breakout)
• S302 (4wd harness, approx 10 cm from transfer case relay breakout)
• Starter relay
• Stoplamp relay
• Transfer case relay
• Under- hood lamp
• Under- hood reel lamp
• Underhood fuse- relay center
• Water-in- fuel sensor

HEADLIGHTS

Headlight Wiring Diagram, with Quad Headlamps for GMC Cab & Chassis K1997 3500

List of elements for Headlight Wiring Diagram, with Quad Headlamps for GMC Cab & Chassis K1997 3500:

• (forward lamps harn, approx 12cm from left headlamp breakout toward windshield washer pump)
• (i/p harn, near strng col harn breakout; except 1998 gas) (i/p harn, near auxiliary power outlet; 1998 gas)
• Acc
• Brake ind ctrl
• Brake warn in
• Bulb test
• Convenience center (under left side of dash)
• Daytime running lamps module (behind left side of dash)
• Daytime running lamps relay
• Diode 203 (i/p harness, right side of steering column)
• Drl indicator
• Drl relay ctrl
• Drl-fog fuse 15 20a
• Exterior lights system
• Fog lamp relay
• Fog lamp switch
• G101 (right inner fender)
• G101 (right inner fender, below underhood reel lamp)
• G108 (left radiator support)
• G134 (front top of engine)
• G202 (behind left side of dash)
• Gages fuse 4 10a
• Ground
• Head
• Head- lamp dimmer switch
• Headlamp and panel dimmer switch
• High beam indicator
• Hot at all times
• Hot in run, bulb test or start
• I/p fuse block (left side of dash)
• Ignition
• Ignition switch
• Illum lamp
• Ind bulb chk
• Instrument cluster
• Instrument cluster system (brake warning indicator)
• Interior lights system
• Lamp feed
• Left fog lamp
• Left high beam head- lamp
• Left low beam head- lamp
• Lighting fuse 8 50a
• Lock
• Nca
• Off
• On indicator
• Park
• Park brake sig
• Park brake warning switch
• Pk lps fuse 9 20a
• Pnk
• Red
• Red c
• Right fog lamp
• Right high beam head- lamp
• Right low beam head- lamp
• Run
• S120 (forward lamps harn, near windshield washer pump breakout toward left hdlp)
• S121
• S123
• S125 (i/p harn, approx 13cm from left rear engine compt grommet towards forward lamps harn; except 1998 diesel) (i/p harn, approx 20cm from cluster breakout; 1998 diesel)
• S128
• S204
• S205
• S210
• S213
• S215
• S298
• Start
• Tan
• Underhood fuse/relay center (left rear of engine compt)
• W/ fog lamps

Headlight Wiring Diagram, with Sealed Beam Headlamps for GMC Cab & Chassis K1997 3500

List of elements for Headlight Wiring Diagram, with Sealed Beam Headlamps for GMC Cab & Chassis K1997 3500:

• (forward lamps harn, approx 12cm from left headlamp breakout toward windshield washer pump)
• (high)
• (i/p harn, near strng col harn breakout; except 1998 gas) (i/p harn, near auxiliary power outlet; 1998 gas)
• (low)
• Acc
• Brake ind ctrl
• Brake warn in
• Bulb test
• Convenience center (under left side of dash)
• Daytime running lamps module (behind left side of dash)
• Daytime running lamps relay
• Diode 203 (i/p harness, right side of steering column)
• Drl indicator
• Drl relay ctrl
• Drl-fog fuse 15 20a
• Exterior lights system
• Fog lamp relay
• Fog lamp switch
• G101 (right inner fender)
• G101 (right inner fender, below underhood reel lamp)
• G108 (left radiator support)
• G134 (front top of engine)
• G202 (behind left side of dash)
• Gages fuse 4 10a
• Ground
• Head
• Head- lamp dimmer switch
• Headlamp and panel dimmer switch
• High beam indicator
• Hot at all times
• Hot in run, bulb test or start
• I/p fuse block (left side of dash)
• Ignition
• Ignition switch
• Illum lamp
• Ind bulb chk
• Instrument cluster
• Instrument cluster system (brake warning indicator)
• Interior lights system
• Lamp feed
• Left fog lamp
• Left head- lamp
• Lighting fuse 8 50a
• Lock
• Nca
• Off
• On indicator
• Park
• Park brake sig
• Park brake warning switch
• Pk lps fuse 9 20a
• Pnk
• Red
• Red c
• Right fog lamp
• Right head- lamp
• Run
• S120 (forward lamps harn, near windshield washer pump breakout toward left headlamp)
• S121
• S123
• S125 (i/p harn, approx 13cm from left rear engine compt grommet towards forward lamps harn; except 1998 diesel) (i/p harn, approx 20cm from cluster breakout; 1998 diesel)
• S128
• S204
• S205
• S210
• S213
• S215
• S298
• Start
• Tan
• Tan c
• Underhood fuse/relay center (left rear of engine compt)
• W/ fog lamps

HORN

Horn Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Horn Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (forward lamps harn, 26.5 cm from left headlamp breakout) s124
• G101 (right inner fender, below underhood reel lamp)
• Horn mini fuse 20a
• Horn relay
• Horn slip ring
• Horn switch
• Hot at all times
• Left horn (front of vehicle)
• Nca
• Right horn (front of vehicle)
• S128
• Steering wheel
• Underhood fuse-relay center

INSTRUMENT CLUSTER

5.0L

5.0L (VIN M), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (6 bulbs)
• (engine harn, 20 cm into ebcm breakout)
• A/t
• Accy
• Air bag
• Anti- lock brakes
• Anti-lock brakes system
• Balance fuel gage sender (in rear fuel tank)
• Bat
• Belt
• Brake
• Brake ind in
• Brake pressure modulator valve (left front wheelhouse)
• Brake pressure warning switch (on rear of brake pressure modulator valve body)
• Bulb test
• C100
• Check gauges
• Check gauges lamp driver
• Daytime running lamps
• Daytime running lamps module (left side of i/p)
• Diode 1
• Engine controls system (fuel pump balance relay)
• Engine coolant temperature sender (left cylinder head)
• Exterior lights system
• Fuel gauge
• Fuel pump & sender (in front fuel tank)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (near transmission crossmember)
• Fuel pump/ oil pressure switch & sender (left rear side of engine)
• G119 (near thermostat housing)
• G119 (right front of engine block)
• Gauges fuse 4 10a
• Headlights system
• Hi beam
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block (behind left side of i/p)
• Ign
• Ign e mini fuse 10a
• Ignition coil (right rear side of engine)
• Ignition switch
• Illum
• Illumination
• Instrument cluster
• Interior lights system
• Led dimming
• Left turn
• Lock
• M/t
• Mil ind
• Off
• Oil gauge
• Parity prndl
• Park brake warning switch (left side of i/p)
• Pnk
• Prndl
• Prndl a
• Prndl b
• Prndl c
• Right turn
• Run
• S103
• S146
• S147
• S157
• S162
• S213
• S215
• S317
• Safety
• Service engine soon
• Speedo
• Speedometer
• Start
• Starting/charging system
• Tach
• Tan
• Temp gauge
• Trans fuse 20 10a
• Transmission range selector (left side of transmission)
• Twisted pair
• Underhood fuse- relay center
• Underhood fuse-relay center (left rear of engine compt)
• Upshift (m/t only)
• Upshift ind
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left rear of transmission)
• Voltmeter
• Vss
• W/ dual fuel tanks
• W/o dual fuel tanks
• Warning systems

5.7L

5.7L (VIN R), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (6 bulbs)
• (engine harn, 20 cm into ebcm breakout)
• A/t
• Accy
• Air bag
• Anti- lock brakes
• Anti-lock brakes system
• Balance fuel gage sender (in rear fuel tank)
• Bat
• Belt
• Brake
• Brake ind in
• Brake pressure modulator valve (left front wheelhouse)
• Brake pressure warning switch (on rear of brake pressure modulator valve body)
• Bulb test
• C100
• Check gauges
• Check gauges lamp driver
• Daytime running lamps
• Daytime running lamps module (left side of i/p)
• Diode 1
• Engine controls system (fuel pump balance relay)
• Engine coolant temperature sender (left cylinder head)
• Exterior lights system
• Fuel gauge
• Fuel pump & sender (in front fuel tank)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (near transmission crossmember)
• Fuel pump/ oil pressure switch & sender (left rear side of engine)
• G119 (near thermostat housing)
• G119 (right front of engine block)
• Gauges fuse 4 10a
• Headlights system
• Hi beam
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block (behind left side of i/p)
• Ign
• Ign e mini fuse 10a
• Ignition coil (right rear side of engine)
• Ignition switch
• Illum
• Illumination
• Instrument cluster
• Interior lights system
• Led dimming
• Left turn
• Lock
• M/t
• Mil ind
• Off
• Oil gauge
• Parity prndl
• Park brake warning switch (left side of i/p)
• Pnk
• Prndl
• Prndl a
• Prndl b
• Prndl c
• Right turn
• Run
• S103
• S146
• S147
• S157
• S162
• S213
• S215
• S317
• Safety
• Service engine soon
• Speedo
• Speedometer
• Start
• Starting/charging system
• Tach
• Tan
• Temp gauge
• Trans fuse 20 10a
• Transmission range selector (left side of transmission)
• Twisted pair
• Underhood fuse- relay center
• Underhood fuse-relay center (left rear of engine compt)
• Upshift (m/t only)
• Upshift ind
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left rear of transmission)
• Voltmeter
• Vss
• W/ dual fuel tanks
• W/o dual fuel tanks
• Warning systems

6.5L

6.5L (VIN F), Instrument Cluster Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Instrument Cluster Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500:

• (6 bulbs)
• Air bag
• Anti- lock brakes
• Anti-lock brakes system
• Bat
• Brake
• Check gauges
• Check gauges lamp driver
• Daytime running lamps
• Engine controls system
• Engine coolant temperature sender (left side of engine block)
• Exterior lights system
• Fuel gauge
• G117 (top rear of right cylinder head)
• G202 (left side of i/p)
• Generator
• Gnd
• Headlights system
• Hi beam
• Ign
• Illum
• Illumination
• Instrument cluster
• Interior lights system
• Led dimming
• Left turn
• Low coolant
• Low coolant level indicator module (under center of i/p)
• Low coolant level sensor (in coolant reservoir)
• Oil press
• Oil pressure switch & sender (left rear side of engine)
• Parity prndl
• Pnk
• Prndl
• Prndl a
• Prndl b
• Prndl c
• Right turn
• S107
• S147
• S215
• S298
• Safety belt
• Service engine soon
• Service throttle soon
• Solid state
• Speed- ometer
• Starting/charging system
• System engine controls system
• Tach
• Tan
• Temp gauge
• Transmission range selector (left side of transmission)
• Up- shift
• Volt- meter
• Wait to start
• Warning system
• Water in fuel
• Water-in fuel sensor

6.5L (VIN F), Instrument Cluster Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Instrument Cluster Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500:

• (engine harn, 20 cm into ebcm breakout)
• (i/p harn, 18 cm into cluster breakout)
• (i/p harn, 5 cm into power steering control module breakout)
• A/t
• Accy
• Anti-lock brakes system
• Balance fuel gage sender (in rear fuel tank)
• Brake ind in
• Brake pressure modulator valve (left front wheelhouse)
• Brake pressure warning switch (on rear of brake pressure modulator valve body)
• Bulb test
• C100
• Daytime running lamps module (left side of i/p)
• Diode 1
• Eng 1 mini fuse 20a
• Engine controls system
• Engine controls system (fuel pump balance relay)
• Fuel gage sender
• Fuel pump & sender
• Fuel pump balance module (inside left side of frame rail near trans. crossmember)
• G117 (top rear of right cylinder head)
• Gauges fuse 4 10a
• Hot in run, bulb test or start
• I/p fuse block (behind left side of i/p)
• Ign e mini fuse 10a
• Ignition switch
• Lock
• M/t
• Off
• Park brake warning switch (left side of i/p)
• Pnk
• Radio
• Run
• S103
• S107
• S108
• S157
• S211
• S213
• S215
• S221
• S315
• S317
• Start
• Trans fuse 20 10a
• Transmission system
• Twisted pair
• Underhood fuse-relay center (left rear of engine compt)
• Vehicle speed sensor (left rear of transmission)
• Vehicle speed sensor buffer (behind right side of i/p)
• W/ dual fuel tanks
• W/o dual fuel tanks

6.5L (VIN S), Instrument Cluster Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Instrument Cluster Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500:

• (6 bulbs)
• Air bag
• Anti- lock brakes
• Anti-lock brakes system
• Bat
• Brake
• Check gauges
• Check gauges lamp driver
• Daytime running lamps
• Engine controls system
• Engine coolant temperature sender (left side of engine block)
• Exterior lights system
• Fuel gauge
• G117 (top rear of right cylinder head)
• G202 (left side of i/p)
• Generator
• Gnd
• Headlights system
• Hi beam
• Ign
• Illum
• Illumination
• Instrument cluster
• Interior lights system
• Led dimming
• Left turn
• Low coolant
• Low coolant level indicator module (under center of i/p)
• Low coolant level sensor (in coolant reservoir)
• Oil press
• Oil pressure switch & sender (left rear side of engine)
• Parity prndl
• Pnk
• Prndl
• Prndl a
• Prndl b
• Prndl c
• Right turn
• S107
• S147
• S215
• S298
• Safety belt
• Service engine soon
• Service throttle soon
• Solid state
• Speed- ometer
• Starting/charging system
• System engine controls system
• Tach
• Tan
• Temp gauge
• Transmission range selector (left side of transmission)
• Up- shift
• Volt- meter
• Wait to start
• Warning system
• Water in fuel
• Water-in fuel sensor

6.5L (VIN S), Instrument Cluster Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Instrument Cluster Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500:

• (engine harn, 20 cm into ebcm breakout)
• (i/p harn, 18 cm into cluster breakout)
• (i/p harn, 5 cm into power steering control module breakout)
• A/t
• Accy
• Anti-lock brakes system
• Balance fuel gage sender (in rear fuel tank)
• Brake ind in
• Brake pressure modulator valve (left front wheelhouse)
• Brake pressure warning switch (on rear of brake pressure modulator valve body)
• Bulb test
• C100
• Daytime running lamps module (left side of i/p)
• Diode 1
• Eng 1 mini fuse 20a
• Engine controls system
• Engine controls system (fuel pump balance relay)
• Fuel gage sender
• Fuel pump & sender
• Fuel pump balance module (inside left side of frame rail near trans. crossmember)
• G117 (top rear of right cylinder head)
• Gauges fuse 4 10a
• Hot in run, bulb test or start
• I/p fuse block (behind left side of i/p)
• Ign e mini fuse 10a
• Ignition switch
• Lock
• M/t
• Off
• Park brake warning switch (left side of i/p)
• Pnk
• Radio
• Run
• S103
• S107
• S108
• S157
• S211
• S213
• S215
• S221
• S315
• S317
• Start
• Trans fuse 20 10a
• Transmission system
• Twisted pair
• Underhood fuse-relay center (left rear of engine compt)
• Vehicle speed sensor (left rear of transmission)
• Vehicle speed sensor buffer (behind right side of i/p)
• W/ dual fuel tanks
• W/o dual fuel tanks

7.4L

7.4L (VIN J), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Instrument Cluster Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (6 bulbs)
• (engine harn, 20 cm into ebcm breakout)
• A/t
• Accy
• Air bag
• Anti- lock brakes
• Anti-lock brakes system
• Balance fuel gage sender (in rear fuel tank)
• Bat
• Belt
• Brake
• Brake ind in
• Brake pressure modulator valve (left front wheelhouse)
• Brake pressure warning switch (on rear of brake pressure modulator valve body)
• Bulb test
• C100
• Check gauges
• Check gauges lamp driver
• Daytime running lamps
• Daytime running lamps module (left side of i/p)
• Diode 1
• Engine controls system (fuel pump balance relay)
• Engine coolant temperature sender (left cylinder head)
• Exterior lights system
• Fuel gauge
• Fuel pump & sender (in front fuel tank)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (near transmission crossmember)
• Fuel pump/ oil pressure switch & sender (left rear side of engine)
• G119 (near thermostat housing)
• G119 (right front of engine block)
• Gauges fuse 4 10a
• Headlights system
• Hi beam
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block (behind left side of i/p)
• Ign
• Ign e mini fuse 10a
• Ignition coil (right rear side of engine)
• Ignition switch
• Illum
• Illumination
• Instrument cluster
• Interior lights system
• Led dimming
• Left turn
• Lock
• M/t
• Mil ind
• Off
• Oil gauge
• Parity prndl
• Park brake warning switch (left side of i/p)
• Pnk
• Prndl
• Prndl a
• Prndl b
• Prndl c
• Right turn
• Run
• S103
• S146
• S147
• S157
• S162
• S213
• S215
• S317
• Safety
• Service engine soon
• Speedo
• Speedometer
• Start
• Starting/charging system
• Tach
• Tan
• Temp gauge
• Trans fuse 20 10a
• Transmission range selector (left side of transmission)
• Twisted pair
• Underhood fuse- relay center
• Underhood fuse-relay center (left rear of engine compt)
• Upshift (m/t only)
• Upshift ind
• Vehicle control module (left front wheelhouse)
• Vehicle speed sensor (left rear of transmission)
• Voltmeter
• Vss
• W/ dual fuel tanks
• W/o dual fuel tanks
• Warning systems

INTERIOR LIGHTS

Courtesy Lamps Wiring Diagram, Regular Cab/Extended Cab for GMC Cab & Chassis K1997 3500

List of elements for Courtesy Lamps Wiring Diagram, Regular Cab/Extended Cab for GMC Cab & Chassis K1997 3500:

• (crossbody harn, approx 41 cm from left door harn breakout)
• (i/p harn, arrrox 8 cm in crossbody harn breakout) s208
• (not used)
• Bat
• C210
• C219
• C220
• Cargo lamp
• Conven- ience center (left side of i/p)
• Convenience center (left side of i/p)
• Courtesy lamps
• Ctrl
• Ctsy fuse 3 20a
• Dome defeat
• Dome lamp defeat
• Door jamb
• Front dome lamp
• G120 (diesel) (right top of cylinder head)
• G120 (gasoline) (right front of engine block
• G202 (left side of i/p)
• Gages fuse 4 10a
• Gnd
• Headlamp and panel dimmer switch
• Horn mini fuse 20a
• Hot at all times
• Hot in run, bulb test or start
• I/p compartment box lamp
• I/p fuse block
• Ign sw
• Interior lamp control module (under center of i/p)
• Lamp out
• Left front door jamb switch
• Left i/p courtesy lamp
• Left illuminated vanity mirror
• Mirrors system
• Pnk
• Pnk a
• Pnk j
• Rear door speaker breakout)
• Remote control door lock receiver (under center of i/p)
• Right front door jamb switch
• Right i/p courtesy lamp
• Right illuminated vanity mirror
• S113
• S162 (gas) s147 (diesel)
• S204
• S209 (i/p harn, approx 12 cm in crossbody harn breakout)
• S213
• S218
• S242
• S246
• S248
• S251
• S312
• S316
• Underhood fuse-relay center
• Underhood lamp
• Underhood reel lamp
• W/ rke
• W/o rke

Instrument Illumination Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500

List of elements for Instrument Illumination Wiring Diagram (1 of 2) for GMC Cab & Chassis K1997 3500:

• (6) bulbs
• (at right "b" pillar)
• (cross- body harn, near i/p harn breakout) s253
• (left side of i/p)
• Audio alarm module (left side of i/p)
• C210
• Cargo lamp switch
• Convenience center (left side of i/p)
• Display dim sig
• Fog lamp switch
• Front auxiliary a/c-heater control module
• G120 (diesel) (right top of cylinder head)
• G131 (gas) (near thermostat housing)
• G202
• G305
• Headlamp and panel dimmer switch
• Heater and a/c control
• Hot at all times
• I/p fuse block
• I/p fuse block (left side of i/p)
• Illum fuse 14 10a
• Inflatable restaint i/p module enable switch
• Instrument cluster
• Off
• Parade mode sw
• Park
• Park lps fuse 9 20a
• Pickup/ extended cab only
• Radio
• Rear auxiliary a/c-heater control module
• Rear auxiliary heater switch
• Rear liftgate release switch
• Rear window wiper/ washer switch
• Rheo- stat
• S204
• S215
• S216 (i/p harn, near i/p cluster breakout)
• S217 (i/p harn, near i/p cluster breakout)
• S218
• S259
• S307
• Suburban & utility only
• Transfer case mode selector illuminator lamp
• Transfer case select switch

Instrument Illumination Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500

List of elements for Instrument Illumination Wiring Diagram (2 of 2) for GMC Cab & Chassis K1997 3500:

• (crossbody harn, approx 6 cm in left door harn breakout)
• (left side of i/p)
• Ash tray lamp
• C210
• Convenience center (left side of i/p)
• Exterior lights system
• G202
• Headlamp and panel dimmer switch
• Hot at all times
• I/p fuse block
• Left front power window switch
• Left rear power window switch
• Off
• Parade mode sw
• Park
• Park lps fuse 9 20a
• Rear window lockout switch
• Remote outside rearview mirror switch
• Rheo- stat
• Right front power window switch
• Right rear power window switch
• S204
• S210 (i/p harn, approx 12 cm from steering column harn breakout)
• S218
• S247
• S251
• S259
• S500
• S502 (left front door harn, near tweeter)

POWER DISTRIBUTION

Power Distribution Wiring Diagram (1 of 4) for GMC Cab & Chassis K1997 3500

List of elements for Power Distribution Wiring Diagram (1 of 4) for GMC Cab & Chassis K1997 3500:

• (diesel)
• (diesel-engine harness, approx 5 cm from break- out to glow plug relay, gasoline-engine harness, approx 11 cm into under- hood fuse-relay center breakout)
• (engine harness, 4-13 cm from fuse-relay center breakout)
• (engine harness, approx 18 cm into underhood fuse-relay center break- out) s113
• (except diesel)
• (gasoline)
• (i/p harness, approx 5 cm from dlc harness breakout) s205
• (rear heat and a/c harness, 11-23 cm from blower motor relays breakout) s401
• (stud a)
• (stud b)
• (vanity mirror jumper harness, approx 4 cm from inside rearview mirror)
• A/c comp mini fuse 20a
• A/c maxi fuse 3 50a
• A/c relay
• Aux fan relay mini fuse 20a
• Auxiliary cooling fan relay
• Blower relay
• Brake lamp relay
• C13
• C205
• C219
• Cargo lamp switch (pick-up only)
• Convenience center
• Ctsy fuse 3 20a
• D13
• Daytime running lamps relay
• Diesel
• Diode
• Drl/fog fuse 15 20a
• Ecm-b mini fuse 20a
• Electronic brake control module
• Fog lamp relay
• Front dome reading lamps
• Fuel pump oil pressure switch and sender
• Fuel pump relay
• Fusible link (10 ga-rust)
• Gas
• Generator
• Headlamp and panel dimmer switch
• Heater and a/c control switch
• High blower relay
• Horn mini fuse 20a
• Horn relay
• I/p compartment lamp
• I/p fuse block
• Interior lamp control module
• Left battery (diesel)
• Left courtesy lamp
• Left front door courtesy lamp
• Left illuminated vanity mirror
• Left rear door courtesy lamp
• Low blower relay
• Maxi fuse 2 30a
• Maxi fuse 30a
• Maxi fuse 4 60a
• Maxi fuse 8 50a
• Medium blower relay
• Pk lps fuse 9 20a
• Powertrain control module (diesel)
• Rear dome reading lamps
• Red
• Remote battery stud
• Remote outside rearview mirror switch
• Right battery
• Right courtesy lamp
• Right front door courtesy lamp
• Right illuminated vanity mirror
• Right rear door courtesy lamp
• Rr defog mini fuse 20a
• S101
• S110 red
• S242 (i/p harness, approx 12 cm from radio harness breakout)
• S248 (crossbody harness, approx 35 cm from rear speaker breakout)
• S312
• Spare power source
• Starter motor solenoid
• To fusible link (diagram 4 of 4)
• To underhood fuse-relay center (diagram 2 of 4)
• Underhood fuse- relay center
• Underhood fuse-relay center
• Underhood lamp
• Underhood reel lamp
• Vehicle control module (gasoline)

Power Distribution Wiring Diagram (2 of 4) for GMC Cab & Chassis K1997 3500

List of elements for Power Distribution Wiring Diagram (2 of 4) for GMC Cab & Chassis K1997 3500:

• (crossbody harness, approx 11 cm from convenience center connector breakout) s255
• (crossbody harness, approx 8 cm right of i/p cluster
• (i/p harness, approx 12 cm into steering column harness breakout)
• (i/p harness, approx 4 cm from i/p cluster breakout)
• (i/p harness, approx 4 cm into auxiliary power outlet)
• (i/p harness, approx 4 cm into transfer case control module breakout)
• (i/p harness, approx 8 cm from dlc breakout) s200
• (inside left front door harness, near tweeter)
• (pickup-crossbody harness, approx 9 cm from i/p cluster breakout, crewcab-cross- body harness, approx 1 cm from door lock relay breakout, others-crossbody harness, approx 6 cm from door lock relay breakout)
• (pickup-front to rear body harness, approx 6 cm from front dome lamp harness breakout, suburban w/ rear a/c-front to rear body harness, approx 55 cm from rear dome lamp harness breakout, suburban w/o rear a/c-front to rear body harness, approx 25 cm into crossbody harness breakout)
• (power lumbar seat jumper harness, approx 13 cm from right power seat breakout)
• A/t
• Acc
• Audio alarm module
• Aux/pwr fuse 7 25a
• Auxiliary power connector
• C210
• Cig ltr fuse 13 20a
• Cigar lighter
• Clutch pedal position switch
• Convenience center
• Crank fuse 8 10a
• D14
• D15
• Data link connector
• Door lock control module
• Door lock relay
• From underhood a fuse-relay center (diagram 1 of 4)
• G202 (left side of i/p)
• Harness breakout)
• I/p fuse block
• Ignition switch
• Instrument cluster
• Left front door lock switch
• Left front power lumbar seat switch
• Left power seat
• Lock
• M/t
• Maxi fuse 5 50a
• Maxi fuse 6 40a
• Maxi fuse 7 50a
• Nca
• Off
• Park/neutral position switch
• Pickup
• Pnk
• Power amplifier relay
• Power wdo circuit breaker 30a
• Power window master switch
• Pwr-accy circuit breaker 20a
• Radio
• Radio batt fuse 19 10a
• Radio fuse 17 10a
• Rear door lock switch
• Rear liftgate release switch
• Rear window lockout switch (4-dr)
• Rear window wiper/washer switch (suburban/utility)
• Red
• Remote control door lock receiver
• Right front door lock switch
• Right front power lumbar seat switch
• Right front power window switch (2 dr & utility)
• Rr wiper fuse 23 25a
• Run
• S201
• S218
• S256
• S264
• S266
• S270
• S299
• S300
• S434
• Start
• Starter relay
• Stop/haz fuse 1 20a
• Suburban only
• Suburban/ utility
• T case fuse 2 20a
• Tcc/stoplamp switch
• To i/p fuse block (diagram 4 of 4)
• To security/ strg fuse 21 (diagram 4 of 4)
• To underhood fuse-relay center (diagram 3 of 4)
• Trans fuse 20 10a
• Trans- mission
• Transfer case control module
• Turn/ hazard switch
• Underhood fuse-relay center
• W/bench seat
• W/o bench seat
• Windshield wiper motor module
• Windshield wiper/ washer switch
• Wiper fuse 11 25a

Power Distribution Wiring Diagram (3 of 4) for GMC Cab & Chassis K1997 3500

List of elements for Power Distribution Wiring Diagram (3 of 4) for GMC Cab & Chassis K1997 3500:

• (a/t)
• (engine harness, approx 11 cm into fuse-relay center breakout) pnk
• (engine harness, approx 11-13 cm from ignition coil breakout)
• (engine harness, approx 22 cm into underhood fuse- relay center breakout)
• (engine harness, approx 29 cm from fuse-relay center breakout)
• (engine harness, approx 30 cm from egr harness breakout)
• (engine harness, approx 5 cm from backup lamp switch harness breakout)
• (engine harness, approx 7 cm from egr breakout)
• (engine harness, approx 8 cm into breakout to fuel injector connector)
• (i/p harness, approx 10 cm from tcc/ stoplamp switch connector breakout) pnk
• (i/p harness, approx 13 cm from dlc harness breakout)
• (in injector harness jumper)
• (m/t)
• (oxygen sensor jumper harness, approx 17 cm into harness)
• (taillamp extension harness, approx 65 cm from fuel pump balance module breakout)
• 4.3l
• 5.0l, 5.7l
• 6.5l
• 7.4l
• 7.4l w/ california emissions
• A/c clutch relay
• Air bag fuse 10 10a
• Air injection reaction secondary relay
• Audio alarm module
• B pnk
• Backup lamp switch
• C pnk
• C11
• C12
• C218
• Camshaft position sensor
• Convenience center
• Crank- shaft position sensor
• Daytime running lamps module
• Daytime running lamps relay
• Diesel
• Diesel only
• Ecm 1 mini fuse 20a
• Egr solenoid
• Egr vent solenoid
• Electrochromatic mirror w/ compass
• Electronic injection pump
• Eng-1 mini fuse 20a
• Evaporative emission canister vent
• Evaporative emissions canister purge solenoid valve
• Exhaust gas recirculation valve
• From ignition switch (diagram 2 of 4)
• Fuel heater
• Fuel injector
• Fuel pump balance module
• Fuel pump balance relay
• Fuel sol mini fuse 20a
• Fuel tank sender module (4.3l)
• Gasoline
• Gauges fuse 4 10a
• Glow plug control module
• Headlamp/ panel dimmer switch
• Heated oxygen sensor 1
• Heated oxygen sensor 2
• Heated oxygen sensor 3
• Heated oxygen sensor 4
• I/p cluster
• I/p fuse block
• Ign e mini fuse 10a
• Ignition coil
• Ignition control module
• Inflatable restraint i/p module enable switch
• Inflatable restraint sensing and diagnostic module
• Interior lamp control module or remote control door lock receiver
• Low coolant level indicator module (diesel)
• M/t
• Mass air flow sensor
• Mass airflow sensor
• Nca
• Nca
• Others
• Pnk
• Pnk s104
• Pnk s154
• Pnk s207
• Power steering control module
• Powertrain control module
• S104
• S108
• S109
• S146
• S148
• S155 pnk
• S161
• S213 pnk
• S315
• Transfer case control module
• Transfer case select switch
• Turn b/u fuse 16 20a
• Turn signal switch
• Underhood fuse-relay center
• Vehicle control module
• Vehicle speed sensor buffer (diesel)
• Wastegate solenoid
• Water-in- fuel sensor

Power Distribution Wiring Diagram (4 of 4) for GMC Cab & Chassis K1997 3500

List of elements for Power Distribution Wiring Diagram (4 of 4) for GMC Cab & Chassis K1997 3500:

• (engine harness, approx 6 cm into ebcm breakout)
• (hvac harness, approx 4 cm from recirculation door breakout) s243
• (i/p harness, approx 29 cm from tcc/stoplamp switch)
• (i/p harness, approx 4 cm from steering column breakout)
• (i/p harness, approx 6 cm into heater a/c control connector breakout)
• (rear a/c-rear a/c harness, approx 17 cm from blower motor relays, rear heat and a/c-rear heat and a/c harness, approx 4 cm from blower motor relays)
• (rear hvac control harness, approx 5 cm from hvac logic module breakout) s308
• 4wd fuse 24 25a
• A13
• Auxiliary battery
• Auxiliary battery relay (left rear of engine compt)
• Auxiliary heater and a/c control logic module
• Auxiliary heater and a/c control module (front)
• Auxiliary heater and a/c control module (rear)
• Brake fuse 18 10a
• C205
• Convenience center
• Cruise control module
• Cruise control switch
• Cruise fuse 6 10a
• Diesel
• Electronic brake control module
• Except diesel
• From ignition switch (diagram 2 of 4)
• From stop/haz fuse 1 (diagram 2 of 4)
• From underhood fuse-relay center (diagram 1 of 4)
• Front mode door motor
• Front temperature door motor
• Fusible link
• G100 (left front fender)
• Heater and a/c control module
• Heater and a/c control switch
• Htr-a/c fuse 12 25a
• I/p fuse block
• Illum fuse 14 10a
• Interior lights system
• Interior lights system (headlamp and panel lamp dimmer)
• Power steering control module
• Rear auxiliary mode door motor
• Rear auxiliary temperature door motor
• Rear high blower relay
• Rear low blower relay
• Rear medium blower relay
• Recirculation door motor
• Rr hvac fuse 5 20a
• S151
• S206
• S235
• S268
• S400
• Security/ strg fuse 21 10a
• Spare power source
• Tcc/ stoplamp switch
• Transfer case select switch
• Vehicle control module

POWER DOOR LOCKS

Door Lock Wiring Diagram, without Crew Cab for GMC Cab & Chassis K1997 3500

List of elements for Door Lock Wiring Diagram, without Crew Cab for GMC Cab & Chassis K1997 3500:

• (inside right door harness) s601
• (w/ pwr wdo) (w/o pwr wdo)
• (w/ pwr windows) (w/o pwr windows)
• A a
• B e
• C d
• Convenience center (under left side of dash)
• E h
• G202 (below left side of dash)
• Hot at all times
• I/p fuse block (lower left side of dash)
• Left front door lock actuator
• Left front door lock switch
• Lock
• Pwr acc c.b. 20a
• Right front door lock actuator
• Right front door lock switch
• S204
• S255
• S500
• S600 (inside right door harness)
• Solid state
• Tan
• Unlock

Keyless Entry Wiring Diagram, without Crew Cab for GMC Cab & Chassis K1997 3500

List of elements for Keyless Entry Wiring Diagram, without Crew Cab for GMC Cab & Chassis K1997 3500:

• (crossbody harness, near door lock relay breakout) s256
• Batt (b+)
• C210
• Cig ltr fuse 13 20a
• Convenience center (left side of dash)
• Data link connector (under left side of dash)
• Dome lamps
• Dome lmp off
• Door lock relay (under center of dash, near remote control door lock receiver)
• Driver dr unlk
• G202 (left end of i/p, near fuse block)
• Gauges fuse 4 10a
• Ground
• Hot at all times
• Hot in run, bulb test or start
• I/p fuse block (left side of dash)
• Ignition
• Interior lamps system
• Left door lock switch
• Left front door lock actuator
• Lock
• Lock out
• Pass drs unlk
• Pnk
• Program sig
• Pwr accy c.b. 30a
• Remote control door lock receiver (under center of dash panel)
• Right door lock switch
• Right front door lock actuator
• S213
• S251
• S255
• S257 (crossbody harness, near door lock relay harness breakout)
• S258 (crossbody harn, under left side of dash)
• S260 (cross body harness, 6cm from seat belt switch breakout)
• S261 (crossbody harness, 12cm from seat belt switch breakout)
• Tan
• Unlock
• Unlock out
• W/ power windows
• W/o power windows

POWER MIRRORS

Power Mirror Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Power Mirror Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (inside left front door harness)
• (inside right front door harness)
• Convenience center (behind left side of i/p)
• Ctsy fuse 3 20a
• Down
• G202 (behind left side of i/p)
• Hot at all times
• I/p fuse block
• Illum- nation lamp
• Interior lights system
• Left
• Left outside power rearview mirror
• Left/ right motor
• Power outside rearview mirror switch
• Red
• Right
• Right outside power rearview mirror
• S204
• S248
• S251
• S503
• S602
• Up/ down motor

POWER SEATS

6-Way Power Seat Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for 6-Way Power Seat Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (behind left side of i/p)
• (crossbody harn, approx 12.5 cm right of left door harn breakout, toward i/p harn breakout)
• (power lumbar seat jumper, approx 20 cm from right power seat breakout)
• (w/ reg/extended cab) (except reg/extended cab)
• Back
• C210
• Convenience center (under left side of i/p)
• Down
• Entire seat
• For- ward
• Forward/ rearward motor
• Front height
• Front tilt motor
• G202
• Hot at all times
• I/p fuse block (left side of i/p)
• Lumbar support circuit
• Power seat switch
• Pwr accy circuit breaker 20a 30a
• Rear height
• Rear tilt motor
• S204
• S251
• S255 (crossbody harn, approx 11.5 cm from convenience center breakout)
• Tan

Lumbar Wiring Diagram, Bench Seat for GMC Cab & Chassis K1997 3500

List of elements for Lumbar Wiring Diagram, Bench Seat for GMC Cab & Chassis K1997 3500:

• (crossbody harn, approx 6 cm from door lock relay breakout)
• (front to rear body harn, approx 6 cm from left kick panel breakout)
• (power lumbar seat jumper harn, approx 13.5 cm from right power seat breakout)
• C210 b
• Cig ltr fuse 13 20a
• Convenience center (under left side of i/p)
• G202 (behind left side of i/p)
• Hot at all times
• I/p fuse block (lower left side of i/p)
• Left power lumbar support switch
• Pnk
• Power lumbar motor
• Right power lumbar support switch
• S204
• S251
• S256
• S264 (suburban utility only)
• S300
• S310 (suburban)

Lumbar Wiring Diagram, Bucket And Split Bench Seat for GMC Cab & Chassis K1997 3500

List of elements for Lumbar Wiring Diagram, Bucket And Split Bench Seat for GMC Cab & Chassis K1997 3500:

• (crossbody harn, approx 6 cm from door lock relay breakout)
• 6-way power seat circuit
• Cig ltr fuse 13 20a
• Convenience center (under left side of i/p)
• G202 (behind left side of i/p)
• Hot at all times
• I/p fuse block (lower left side of i/p)
• Left power lumbar support motor
• Left power lumbar support switch
• Pnk
• Right power lumbar support motor
• Right power lumbar support switch
• S204
• S251
• S259
• S264 (suburban utility only)
• S303

POWER WINDOWS

Power Window Wiring Diagram, 2 Door for GMC Cab & Chassis K1997 3500

List of elements for Power Window Wiring Diagram, 2 Door for GMC Cab & Chassis K1997 3500:

• Convenience center (under left side of i/p)
• Down
• G202 (below left side of i/p)
• Hot in run
• I/p fuse block (lower left side of i/p)
• Interior lights system
• Left front
• Left front window motor
• Left power window master switch
• Pwr wdo circuit breaker 30a
• Right front
• Right front window motor
• Right front window switch
• S204
• S251
• S259
• S266
• S500
• S501
• Solid state
• Tan

Power Window Wiring Diagram, 4 Door for GMC Cab & Chassis K1997 3500

List of elements for Power Window Wiring Diagram, 4 Door for GMC Cab & Chassis K1997 3500:

• (crossbody harn, approx 25cm from seat belt sw breakout toward i/p harn breakout)
• Convenience center (under left side of i/p)
• Down
• Fuse block (lower left side of i/p)
• G202 (below left side of i/p)
• Headlamp and panel dimmer switch
• Hot at all times
• Hot in run
• Left front
• Left front power window master switch
• Left front window motor
• Left rear
• Left rear window motor
• Left rear window switch
• Pk lps fuse 20a
• Pwr wdo circuit breaker 30a
• Right front
• Right front window motor
• Right front window switch
• Right rear
• Right rear window motor
• Right rear window switch
• S204
• S247 (crossbody harn, approx 6cm into left door harn breakout)
• S251
• S263
• S500
• S501
• S502 (left front door harn, near tweeter)
• Solid state
• Tan
• Window lockout switch

RADIO

Radio Wiring Diagrams, with Amplifier for GMC Cab & Chassis K1997 3500

List of elements for Radio Wiring Diagrams, with Amplifier for GMC Cab & Chassis K1997 3500:

• (left side of dash) data link connector
• (lf door harn, near window reg breakout)
• (rf door harn, near door lock motor breakout)
• Amp feed
• Antenna
• Audio rtn
• Bare
• Battery
• Cig ltr fuse 13 20a
• Diesel
• Dim
• Dim feed
• Display dim
• Drain rtn
• E&c diag
• Fuse out
• G201 (right side of dash)
• G202 (left side of dash)
• Gas
• Ground
• Hot at all times
• Hot in acc or run
• I/p fuse block
• Interior lights system
• Left front speaker
• Left front tweeter
• Left rear door speaker
• Left rear speaker
• Lf +
• Lf -
• Lr +
• Lr dr +
• Lr dr -
• Lr _
• Lr+
• Lr-
• Lt audio
• Lt remote
• Nca
• Pnk
• Power amplifier (under left side of dash)
• Power amplifier relay (under left side of dash)
• Radio
• Radio batt fuse 19 10a
• Radio fuse 17 10a
• Red
• Remote audio player
• Remote rtn
• Rf +
• Rf -
• Right front speaker
• Right front tweeter
• Right rear door speaker
• Right rear speaker
• Rly sig
• Rr +
• Rr -
• Rr dr +
• Rr dr -
• Rr+
• Rr-
• Rt audio
• Rt remote
• S221
• S249
• S250
• S251
• S252
• S254
• S256
• S259
• S298
• S504
• S505
• S603
• S604
• Serial data
• Tan
• Tape ctrl
• Vehicle control module (left side of engine compartment)
• Vehicle speed sensor buffer (behind right side of dash)
• Vss signal

Radio Wiring Diagrams, without Amplifier for GMC Cab & Chassis K1997 3500

List of elements for Radio Wiring Diagrams, without Amplifier for GMC Cab & Chassis K1997 3500:

• (left side of dash) data link connector
• (lf door harn, near window reg breakout)
• (rf door harn, near door lock motor breakout)
• Amp feed
• Antenna
• Audio rtn
• Bare
• Battery
• Diesel
• Dim
• Dim feed
• Display dim
• Drain rtn
• E&c diag
• Fuse out
• G202 (left side of dash)
• Gas
• Ground
• Hot at all times
• Hot in acc or run
• I/p fuse block
• Interior lights system
• Left front speaker
• Left front tweeter
• Left rear speaker
• Lf +
• Lf -
• Lr +
• Lr _
• Lt audio
• Lt remote
• Nca
• Pnk
• Radio
• Radio batt fuse 19 10a
• Radio fuse 17 10a
• Remote audio player
• Remote rtn
• Rf +
• Rf -
• Right front speaker
• Right front tweeter
• Right rear speaker
• Rr +
• Rr -
• Rt audio
• Rt remote
• S221
• S298
• S504
• S505
• S603
• S604
• Serial data
• Tan
• Tape ctrl
• Vehicle control module (left side of engine compartment)
• Vehicle speed sensor buffer (behind right side of dash)
• Vss signal

SHIFT INTERLOCKS

Shift Interlock Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Shift Interlock Wiring Diagram for GMC Cab & Chassis K1997 3500:

• Automatic transmission shift lock control (btsi) solenoid (right side of steering column)
• G202 (behind left side of dash)
• Hot in run or start
• I/p fuse block
• Park/ neutral position switch (left side of transmission)
• Pnk
• S204
• Transfer case control module (under dash on steering column support bracket)
• Turn/ hazard switch
• Turn/bu fuse 16 20a
• W/ electric shift transfer case

STARTING/CHARGING

Charging Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Charging Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (diesel)
• (gas)
• (gas-left front of engine, diesel-left front of intake manifold)
• (gasoline)
• (left front of intake manifold)
• (not used)
• (not used) s
• (right front wheelhouse)
• Charge indicator
• Diesel only
• Fusible link (10 ga-rust)
• G101
• G110
• G119 (gas) g110 (diesel)
• G133
• Gauges fuse 4 10a
• Generator
• Hot in run, or start
• I/p fuse block
• Instrument cluster
• Left battery (diesel)
• Pnk
• Power distribution system
• Red
• Right battery
• S213
• Starting circuit
• Tach

Starting Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Starting Wiring Diagram for GMC Cab & Chassis K1997 3500:

• (gas-left front of eng., diesel-left front of intake manifold)
• (left front of intake manifold)
• (right front of engine-gas, rear of right cylinder head-diesel)
• (right front wheelhouse)
• A/t
• Accy
• Battery stud
• Bulb test
• Charging circuit
• Clutch pedal position switch (top of clutch pedal)
• Crank fuse 8 10a
• Diesel
• G101
• G110
• G119 (gas) g110 (diesel)
• G120 (gas) g117 (diesel)
• Gas
• Hold- in coil
• I/p fuse block
• Ignition switch
• Left battery (diesel)
• Lock
• M/t
• Maxi fuse 6 40a
• Nca
• Off
• Pull- in coil
• Red
• Right battery
• Run
• S107
• Start
• Starter motor
• Starter relay
• Starter solenoid
• Transmission range switch (left side of transmission)
• Underhood fuse-relay center

SUPPLEMENTAL RESTRAINTS

Supplemental Restraint Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Supplemental Restraint Wiring Diagram for GMC Cab & Chassis K1997 3500:

• Air bag fuse 10 10a
• Air bag warning indicator
• B nca
• Bar
• Cluster
• Data line
• Data link connector (under left side of i/p)
• Driver high
• Driver low
• Front end discriminating sensor (front center of engine compt)
• G202 (left side of i/p)
• Gauges fuse 10a
• Ground
• Hot in park or headlamp
• Hot in run, bulb test or start
• I/p fuse block
• Ign 1
• Illum fuse 14 10a
• Indicator lamp
• Inflatable restraint i/p module enable switch (center of i/p)
• Inflatable restraint sensing and diagnostic module (below right seat)
• Inflatable restraint steering wheel module
• Instrument
• Interior lights (dimmer swtch)
• Nca
• Pass disable
• Pass enable
• Pass high
• Pass low
• Passenger inflator module (right i/p)
• Pnk
• S213 (i/p harn, near breakout to datalink conn)
• S217 (i/p harn, near breakout to radio harn)
• S218 (i/p harn, near breakout to radio harn) g202 (behind left side of i/p)
• Seat belt sig
• Sensor feed
• Shorting
• Shorting bar
• Sir coil assembly
• Solid state
• Tan
• Warning systems (seat belt switch)

TRANSMISSION

5.0L

5.0L (VIN M), Transmission Wiring Diagram, 4L60-E for GMC Cab & Chassis K1997 3500

List of elements for 5.0L (VIN M), Transmission Wiring Diagram, 4L60-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (left side of transmission-2wd) (left side of transfer case-4wd)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 3-2 ctrl solenoid
• 3-2 downshift sol
• 4wd low signal in
• 5v reference
• Automatic transmission (4l60-e)
• Battery in
• Brake fuse 18 10a
• Brake switch input
• Dash fuse block
• Data class ii
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sens input
• Electronic brake control module
• Eng 1 fuse 20a
• Engine coolant temp sensor (top right front of engine)
• Front wheel lock
• Fuel injectors, ignition control moudule & ignition coil
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (top of right cylinder head)
• Gauges fuse 4 10a
• Hot at all times
• Hot in off, run or start
• Hot in run
• Hot in run or start
• Ignition in
• Instrument cluster
• Maf sensor & heated oxygen sensors
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Press ctrl solenoid
• Range signal "a"
• Range signal "b"
• Range signal "c"
• Red
• S101
• S103
• S108
• S150 (engine harn, 13 cm from bpmv break-out)
• S151
• S161
• S213
• S231 (engine harness, near map or egr break-out)
• Sensor ground
• Sensor return
• Solenoid
• Stoplamp switch (on brake pedal bracket)
• Tan
• Tcc
• Tcc pwm
• Tcc pwm sol
• Tcc sol
• Throttle position sensor (mounted to side of throttle body)
• Tp sens input
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range pressure switch assembly
• Trans range switches
• Trans temp sig in
• Transfer case & axle switches (4wd only)
• Transfer case circuit
• Underhood fuse/relay center
• Vehicle control module (left side of engine compt)
• Vehicle speed sensor
• Vehicle speed sensor adaptor (4wd only)
• Vss hi
• Vss lo

5.7L

5.7L (VIN R), Transmission Wiring Diagram, 4L60-E for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Transmission Wiring Diagram, 4L60-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (left side of transmission-2wd) (left side of transfer case-4wd)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 3-2 ctrl solenoid
• 3-2 downshift sol
• 4wd low signal in
• 5v reference
• Automatic transmission (4l60-e)
• Battery in
• Brake fuse 18 10a
• Brake switch input
• Dash fuse block
• Data class ii
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sens input
• Electronic brake control module
• Eng 1 fuse 20a
• Engine coolant temp sensor (top right front of engine)
• Front wheel lock
• Fuel injectors, ignition control moudule & ignition coil
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (top of right cylinder head)
• Gauges fuse 4 10a
• Hot at all times
• Hot in off, run or start
• Hot in run
• Hot in run or start
• Ignition in
• Instrument cluster
• Maf sensor & heated oxygen sensors
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Press ctrl solenoid
• Range signal "a"
• Range signal "b"
• Range signal "c"
• Red
• S101
• S103
• S108
• S150 (engine harn, 13 cm from bpmv break-out)
• S151
• S161
• S213
• S231 (engine harness, near map or egr break-out)
• Sensor ground
• Sensor return
• Solenoid
• Stoplamp switch (on brake pedal bracket)
• Tan
• Tcc
• Tcc pwm
• Tcc pwm sol
• Tcc sol
• Throttle position sensor (mounted to side of throttle body)
• Tp sens input
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range pressure switch assembly
• Trans range switches
• Trans temp sig in
• Transfer case & axle switches (4wd only)
• Transfer case circuit
• Underhood fuse/relay center
• Vehicle control module (left side of engine compt)
• Vehicle speed sensor
• Vehicle speed sensor adaptor (4wd only)
• Vss hi
• Vss lo

5.7L (VIN R), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500

List of elements for 5.7L (VIN R), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (5.7l) (7.4l)
• (engine harn, 13 cm from bpmv break-out)
• (left rear side of transmission-2wd) (left side of transfer case-4wd)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 4wd low signal in
• 5v reference
• A/t iss hi in
• A/t iss lo in
• Automatic transmission (4l80-e)
• Automatic transmission input shaft speed sensor (on transmission)
• Battery in
• Brake fuse 18 10a
• Brake switch assembly (on brake pedal bracket)
• Brake switch input
• Data class ii
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sens input
• Electronic brake control module
• Eng 1 fuse 20a
• Engine coolant temp sensor (top right front of engine)
• Front wheel lock
• Fuel injectors, ignition control moudule & ignition coil
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (top of right cylinder head)
• Gauges fuse 4 10a
• Headlamp & panel dimmer switch
• Hot at all times
• Hot in run
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block
• Ignition in
• Instrument cluster
• Maf sensor & heated oxygen sensors
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Press ctrl
• Range signal "a"
• Range signal "b"
• Range signal "c"
• Red
• S101
• S103
• S108
• S150
• S151
• S161 s104
• S213
• S231 (engine harness, near map or egr breakout)
• Sensor ground
• Sensor return
• Solenoid
• Tan
• Tcc pwm
• Tcc pwm sol
• Throttle position sensor (mounted to side of throttle body)
• Tp sens input
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range pressure switch assembly
• Trans range switches
• Trans temp sig in
• Transfer case & axle switches
• Underhood fuse/relay center
• Vehicle control module (vcm) (left side of engine compt)
• Vehicle speed sensor
• Vehicle speed sensor adaptor (4wd only)
• Vss hi
• Vss lo

6.5L

6.5L (VIN F), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN F), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (i/p harn, 4 cm from engine harn break-out)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 4wd low signal in
• A/t iss sens hi in
• A/t iss sens in
• A/t iss sens lo in
• A/t iss sensor out
• A12
• Accelerator pedal position module (part of accelerator pedal)
• App 1 5v ref
• App 1 signal in
• App 2 5v ref
• App 2 signal in
• App 3 5v ref
• App 3 signal in
• Automatic transmission
• Automatic transmission input shaft speed sensor (left front of transmission)
• B10
• B12
• Battery in
• Brake fuse 18 10a
• Brake switch assembly (on brake pedal bracket)
• Brake switch in
• C11
• C12
• C13
• C14
• C15
• Class ii data
• D11
• D12
• D13
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sensor in
• Engine coolant temp sensor (near thermostat housing)
• Front wheel lock
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (right top of cylinder head)
• Gauges fuse 4 10a
• Ground
• Hot at all times
• Hot in run
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block
• Ignition in
• Instrument cluster
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Power
• Powertrain control module (right side of dash near blower motor)
• Press ctrl
• Red
• S101
• S103
• S140 (engine sensor harness)
• S150 (engine harness, 13 cm from bpmv harness break-out)
• S152 (engine harn, 4 cm from i/p break-out)
• S211
• S213
• S220 (i/p harn, 12 cm from brake switch connector)
• S299
• Sensor ground
• Solenoid
• Stop/haz fuse 1 20a
• Stoplamp switch in
• Tan
• Tcc pwm
• Tcc pwm sol
• Tft sensor in
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range "a"
• Trans range "b"
• Trans range "c"
• Trans range pressure switch assembly
• Trans range switches
• Transfer case & axle switches
• Transfer case circuit
• Turn/ hazard switch & chime module
• Underhood fuse/relay center
• Vehicle speed sensor (on transmission-2wd) (on transfer case-4wd)
• Vehicle speed sensor (vss) adaptor (4wd only)
• Vehicle speed sensor buffer (right side of dash)
• Vss hi in
• Vss in
• Vss lo in
• Vss out

6.5L (VIN S), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500

List of elements for 6.5L (VIN S), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (i/p harn, 4 cm from engine harn break-out)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 4wd low signal in
• A/t iss sens hi in
• A/t iss sens in
• A/t iss sens lo in
• A/t iss sensor out
• A12
• Accelerator pedal position module (part of accelerator pedal)
• App 1 5v ref
• App 1 signal in
• App 2 5v ref
• App 2 signal in
• App 3 5v ref
• App 3 signal in
• Automatic transmission
• Automatic transmission input shaft speed sensor (left front of transmission)
• B10
• B12
• Battery in
• Brake fuse 18 10a
• Brake switch assembly (on brake pedal bracket)
• Brake switch in
• C11
• C12
• C13
• C14
• C15
• Class ii data
• D11
• D12
• D13
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sensor in
• Engine coolant temp sensor (near thermostat housing)
• Front wheel lock
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (right top of cylinder head)
• Gauges fuse 4 10a
• Ground
• Hot at all times
• Hot in run
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block
• Ignition in
• Instrument cluster
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Power
• Powertrain control module (right side of dash near blower motor)
• Press ctrl
• Red
• S101
• S103
• S140 (engine sensor harness)
• S150 (engine harness, 13 cm from bpmv harness break-out)
• S152 (engine harn, 4 cm from i/p break-out)
• S211
• S213
• S220 (i/p harn, 12 cm from brake switch connector)
• S299
• Sensor ground
• Solenoid
• Stop/haz fuse 1 20a
• Stoplamp switch in
• Tan
• Tcc pwm
• Tcc pwm sol
• Tft sensor in
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range "a"
• Trans range "b"
• Trans range "c"
• Trans range pressure switch assembly
• Trans range switches
• Transfer case & axle switches
• Transfer case circuit
• Turn/ hazard switch & chime module
• Underhood fuse/relay center
• Vehicle speed sensor (on transmission-2wd) (on transfer case-4wd)
• Vehicle speed sensor (vss) adaptor (4wd only)
• Vehicle speed sensor buffer (right side of dash)
• Vss hi in
• Vss in
• Vss lo in
• Vss out

7.4L

7.4L (VIN J), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500

List of elements for 7.4L (VIN J), Transmission Wiring Diagram, 4L80-E for GMC Cab & Chassis K1997 3500:

• (2wd only)
• (4wd only)
• (5.7l) (7.4l)
• (engine harn, 13 cm from bpmv break-out)
• (left rear side of transmission-2wd) (left side of transfer case-4wd)
• 1-2 shift sol
• 1-2 shift solenoid
• 2-3 shift sol
• 2-3 shift solenoid
• 4wd low signal in
• 5v reference
• A/t iss hi in
• A/t iss lo in
• Automatic transmission (4l80-e)
• Automatic transmission input shaft speed sensor (on transmission)
• Battery in
• Brake fuse 18 10a
• Brake switch assembly (on brake pedal bracket)
• Brake switch input
• Data class ii
• Data link connector (under left side of dash)
• Ecm 1 fuse 20a
• Ecm b fuse 20a
• Ect sens input
• Electronic brake control module
• Eng 1 fuse 20a
• Engine coolant temp sensor (top right front of engine)
• Front wheel lock
• Fuel injectors, ignition control moudule & ignition coil
• Fuel pump & oil press switch/ sender & fuel pump relay
• G120 (top of right cylinder head)
• Gauges fuse 4 10a
• Headlamp & panel dimmer switch
• Hot at all times
• Hot in run
• Hot in run or start
• Hot in run, bulb test or start
• I/p fuse block
• Ignition in
• Instrument cluster
• Maf sensor & heated oxygen sensors
• Malfunction indicator lamp
• Mil control
• Pcm ground
• Pcs sol hi out
• Pcs sol lo out
• Pnk
• Press ctrl
• Range signal "a"
• Range signal "b"
• Range signal "c"
• Red
• S101
• S103
• S108
• S150
• S151
• S161 s104
• S213
• S231 (engine harness, near map or egr breakout)
• Sensor ground
• Sensor return
• Solenoid
• Tan
• Tcc pwm
• Tcc pwm sol
• Throttle position sensor (mounted to side of throttle body)
• Tp sens input
• Trans fluid temp sensor
• Trans fuse 20 10a
• Trans range pressure switch assembly
• Trans range switches
• Trans temp sig in
• Transfer case & axle switches
• Underhood fuse/relay center
• Vehicle control module (vcm) (left side of engine compt)
• Vehicle speed sensor
• Vehicle speed sensor adaptor (4wd only)
• Vss hi
• Vss lo

WARNING SYSTEMS

Warning System Wiring Diagrams for GMC Cab & Chassis K1997 3500

List of elements for Warning System Wiring Diagrams for GMC Cab & Chassis K1997 3500:

• Audio alarm module (in convenience center)
• Battery input
• C210
• Convenience center (under left side of i/p)
• Diesel
• Ex diesel
• Fasten belts out
• G120 (right top of cylinder head)
• G134 (front top of engine)
• G202 (behind left side of i/p)
• Gauges fuse 4 10a
• Ground
• Hot at all times
• Hot in park or head
• Hot in run, bulb test or start
• I/p fuse block
• Ign on
• Illum fuse 14 10a
• Instru- ment cluster
• Interior lights system
• Key-in warning
• Key-in warning buzzer switch (left side of steering column)
• Left door jamb switch
• Lights on input
• Pnk
• S204
• S213
• S215
• S217 (i/p harn, approx 5 cm from headlamp switch breakout)
• S259
• S298
• S299
• Safety belts indicator
• Seat belt input
• Seat belt switch (in driver's safety belt buckle)
• Stop/haz fuse 1 20a
• Tan

WIPER/WASHER

Front Wiper/Washer Wiring Diagram for GMC Cab & Chassis K1997 3500

List of elements for Front Wiper/Washer Wiring Diagram for GMC Cab & Chassis K1997 3500:

• Front windshield washer pump motor
• G108 (left radiator support)
• G202 (behind left side of dash)
• Hot in accy or run
• I/p fuse block (under left side of dash)
• Inst wipe
• Low
• Mist
• Nca
• Off
• Pulse
• Red
• S158
• S204
• Solid state
• Wash
• Washer switch
• Windshield wiper motor module (on firewall, behind wiper motor)
• Windshield wiper/ washer switch
• Wiper fuse 11 25a
• Wiper switch