AIR CONDITIONING – GMC Sierra 2500 HD 2008 – SYSTEM WIRING DIAGRAMS

AIR CONDITIONING

Automatic A/C Wiring Diagram (1 of 3) for GMC Sierra 2500 HD 2008

List of elements for Automatic A/C Wiring Diagram (1 of 3) for GMC Sierra 2500 HD 2008:

• (except 6.6l: in engine harness, 23 cm from map sensor breakout)
• (in i/p harness, 13 cm from radio connector breakout) j203
• (left side of headliner) front inside air temperature sensor
• (lower left side of dash) left i/p junction block
• (lower right side of hvac module) blower motor
• (lower right side of hvac module) blower motor control module
• (on right front corner of hvac module) g200
• (under upper left side of dash) upper left air temperature sensor
• (under upper right side of dash) upper right air temperature sensor
• 5v ref
• A/c ind
• A/c low pressure switch (on right side of a/c accumulator)
• A/c on
• Air temp
• Air tmp
• Air tmp sig
• Amb air tmp
• Ambient air temperature sensor (on left side of radiator support)
• Ambient light/ sunload sensor assembly (top center of dash)
• Auto
• B(+)
• Batt pos volt
• Blwr spd
• Colnt lvl
• Computer data lines system
• Defogger system
• Dfrst val
• Engine coolant level switch (6.6l) (on bottom of surge tank)
• Fan dn
• Fan up
• Fresh air
• Frnt dfg
• Frt def
• Fsh air
• G103 (except 4.3l) (on front of right cylinder head)
• G106 (4.3l) (right rear of engine)
• G200 (on right front corner of hvac module)
• G201 (upper left corner of dash)
• Gmlan l
• Ground
• Hvac control module
• Ign 3
• J106
• J206 (in i/p harness, 14.5 cm from x200 breakout)
• J328 (in headliner harness, 5 cm from front inside air temperature sensor breakout)
• L air tmp
• Left sunload sensor
• Left temp control
• Lf sunld
• Logic
• Low ref
• Lw prss
• Mode ctrl
• Mode dn
• Mode up
• Mtr spd ctrl
• Off
• Power distribution system
• R air tmp
• Rear defog
• Rear dfg
• Recir
• Recir ctrl
• Recirc
• Recirc pos
• Red
• Rer def
• Rf sunld
• Right sunload sensor
• Right temp control
• Tan

Automatic A/C Wiring Diagram (2 of 3) for GMC Sierra 2500 HD 2008

List of elements for Automatic A/C Wiring Diagram (2 of 3) for GMC Sierra 2500 HD 2008:

• (left front of engine compt, near fan shroud) engine control module (ecm)
• (lower left side of dash) body control module (bcm)
• (on front of a/c compressor) a/c compressor clutch
• (top left rear of engine) (4.3l) g107
• 4a1
• 4a2
• 4a3
• 4a4
• 4a5
• 4a6
• 4b2
• 4b3
• 4b5
• 4b6
• 6.6l except 6.6l & 4.3l 4.3l
• A/c cmprsr fuse 17 (except 6.6l) fuse 18 (6.6l) 10a
• A/c comp- ressor clutch relay
• A4 x5
• E x4
• Engine coolant temperature (ect) sensor (4.3l: left side of dash) (except 4.3l & 6.6l: on top of engine) (6.6l: top front center of engine)
• Except 6.6l & 6.0l (vin k)
• G102 (except 4.3l & 6.6l) (on lower left front of engine)
• Hot at all times
• Hvac batt fuse 39 10a
• Hvac blwr fuse 70 40a
• Hvac ign fuse 57 (except 6.6l) fuse 55 (6.6l) 10a
• J105
• Pnk
• Red
• Right i/p junction block (in right end of dash)
• Run/ crank relay
• Tan
• Under- hood fuse block (left side of engine compt)

Automatic A/C Wiring Diagram (3 of 3) for GMC Sierra 2500 HD 2008

List of elements for Automatic A/C Wiring Diagram (3 of 3) for GMC Sierra 2500 HD 2008:

• (left side of hvac module) lower left air temperature sensor
• (lower left of hvac module) lower right air temperature sensor
• (near compressor, on a/c high pressure hose) a/c refrigerant pressure sensor
• (on lower right radiator support) g101
• 87a
• Cooling fan diode 1
• Cooling fan diode 2
• Except 6.6l & 6.0l (vin k)
• Fan cntrl relay
• Fan hi relay 1
• Fan lo relay
• Fan-1 fuse 60 40a
• Fan-2 fuse 62 40a
• G100 (on lower left radiator support)
• Hot at all times
• J100
• J101
• Left air temperature actuator (bottom left of hvac module)
• Left engine cooling fan (left front of engine compt)
• Logic
• Mode actuator (left end of hvac module)
• Pwr/ trn relay
• Recirculation actuator (top right side of hvac module)
• Right air temperature actuator (top middle of hvac module)
• Right engine cooling fan (right front of engine compt)
• Tan
• Under- hood fuse block (left side of engine compt)

Compressor Wiring Diagram for GMC Sierra 2500 HD 2008

List of elements for Compressor Wiring Diagram for GMC Sierra 2500 HD 2008:

• (4.3l: top left rear of engine) (6.6l: on front of right cylinder head) (except 4.3l & 6.6l: on lower left front of engine)
• (on front of a/c compressor) a/c compressor clutch
• 4.3l
• 6.6l
• A/c cmprsr fuse 17 (except 6.6l) fuse 16 (6.6l) 10a
• A/c cmprsr relay
• A/c ind
• A/c low pressure switch (on right side of a/c accumulator)
• A/c on
• A/c refrigerant pressure sensor (near compressor, on a/c high pressure hose)
• Automatic a/c
• B(+)
• Computer data lines system
• Engine control module (ecm) (left front of engine compt, near fan shroud)
• Except 4.3l & 6.6l
• G103 (except 4.3l) (on front of right cylinder head)
• G106 (4.3l) (right rear of engine)
• G107 (4.3l) g103 (6.6l) g102 (except 4.3l & 6.6l)
• G200 (on right front corner of hvac module)
• Gmlan l
• Ground
• Hot at all times
• Hvac batt fuse 39 (except 6.6l) fuse 36 (6.6l) 10a
• Hvac control module
• J105
• J106
• J203
• Logic
• Lw prss
• Manual a/c
• Tan
• Under- hood fuse block (left side of engine compt)

Manual A/C Wiring Diagram (1 of 3) for GMC Sierra 2500 HD 2008

List of elements for Manual A/C Wiring Diagram (1 of 3) for GMC Sierra 2500 HD 2008:

• (4.3l) g107
• (4.3l: top left rear of engine) (6.6l: on front of right cylinder head) (except 6.6l & 4.3l: on lower left front of engine)
• (6.6l) g103
• (except 6.6l: in engine harness, 23 cm from map sensor breakout)
• (left front of engine compt, near fan shroud) engine control module (ecm)
• (lower right side of hvac module) blower motor
• (lower right side of hvac module) blower motor control module
• 4.3l
• 5v ref
• 6.6l
• A/c cmprsr fuse 17 (except 6.6l) fuse 18 (6.6l) 10a
• A/c comp- ressor clutch relay
• A/c ind
• A/c low pressure switch (on right side of a/c accumulator)
• A/c on
• B(+)
• Batt pos volt
• Blower motor control switch
• Blwr spd
• Colnt lvl
• Computer data lines system
• Defogger system
• Dfrst val
• Engine coolant level switch (6.6l) (on bottom of surge tank)
• Engine coolant temperature (ect) sensor (4.3l: left side of dash) (except 4.3l & 6.6l: on top of engine) (6.6l: top front center of engine)
• Except 4.3l & 6.6l
• Except 6.6l 6.0l (vin k)
• Fresh air
• Frh air
• G102 (except 6.6l & 4.3l)
• G103 (except 6.6l) (on front of right cylinder head)
• G106 (4.3l) (right rear of engine)
• G200 (on right front corner of hvac module)
• G201 (upper left corner of dash)
• Gmlan l
• Ground
• Hot at all times
• Hvac batt fuse 39 (except 6.6l) fuse 36 (6.6l) 10a
• Hvac blwr fuse 70 (except 6.6l) fuse 65 (6.6l) 40a
• Hvac control module
• Hvac ign fuse 55 (except 6.6l) fuse 52 (6.6l) 10a
• Ign 3
• Interior lights system power distribution system
• J105
• J106
• J203
• Led cntl
• Left i/p junction block (lower left side of dash)
• Logic
• Low ref
• Lw prss
• Mode ctrl
• Mode switch
• Mtr spd ctrl
• Pnk
• R air tmp
• Rear defog
• Rear dfg
• Recir
• Recir ctrl
• Recirc
• Red
• Rer def
• Run/ crank relay
• Tan
• Temperature control switch
• Under- hood fuse block (left side of engine compt)

Manual A/C Wiring Diagram (2 of 3) for GMC Sierra 2500 HD 2008

List of elements for Manual A/C Wiring Diagram (2 of 3) for GMC Sierra 2500 HD 2008:

• (4.3l) g107
• (4.3l: top left rear of engine) (6.6l: on front of right cylinder head) (except 6.6l & 4.3l: on lower left front of engine)
• (6.6l) g103
• (lower left side of dash) body control module (bcm)
• (near compressor, on a/c high pressure hose) a/c refrigerant pressure sensor
• (on front of a/c compressor) a/c compressor clutch
• 4a1
• 4a4
• 4a6
• 4b3
• 4b5
• 87a
• Cooling fan diode 1
• Cooling fan diode 2
• Except 6.6l & 6.0l (vin k)
• Fan cntrl relay
• Fan lo relay
• Fan-1 fuse 60 40a
• Fan-2 fuse 62 40a
• G100 (on lower left rediator support)
• G101 (on lower right radiator support)
• G102 (except 6.6l & 4.3l)
• Hi fan relay
• Hot at all times
• J100
• J101
• J105
• Left engine cooling fan (left front of engine compt)
• Pnk
• Pwr/ trn relay
• Red
• Right engine cooling fan (right front of engine compt)
• Right i/p junction block (in right end of dash)
• Tan
• Under- hood fuse block (left side of engine compt)

Manual A/C Wiring Diagram (3 of 3) for GMC Sierra 2500 HD 2008

List of elements for Manual A/C Wiring Diagram (3 of 3) for GMC Sierra 2500 HD 2008:

• (not used)
• Air temperature actuator (top middle of hvac module)
• Logic
• Mode actuator (left end of hvac module)
• Recirculation actuator (front a/c) (top right side of hvac module)
• Tan