AIR CONDITIONING — GMC Forward Control P3500 1999 — SYSTEM WIRING DIAGRAMS

AIR CONDITIONING

4.3L

4.3L VIN W, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999

List of elements for 4.3L VIN W, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999:

• (at left rear of cylinder head) g114
• (in engine harness approximately 4 cm (2 in) from breakout for 36 pin in-line connector, left side of firewall towards grommet on same) s110
• (in engine harness approximately 7 cm (3 in) from throttle position sensor breakout toward an engine to fuel injector in-line harness connector: (12 pin, 4.3l vin w) (16 pin, 5.7l vin r) s138
• (in engine harness, approximately 11 cm (4 in) from 36 pin in-line connector breakout on left side of firewall, towards grommet on left side of firewall) s144
• (in engine harness, approximately 19 cm (8 in) from 36 pin in-line connector breakout on left side of firewall towards maf sensor) s132
• (left interior bulkhead near relay bracket) g202
• (on left side of radiator support) vehicle control module (vcm)
• 13 cm (5 in) from a/c compressor high pressure cut-off switch breakout) s124
• A/c compressor clutch (left side of engine)
• A/c compressor enable rly ctrl
• A/c compressor high pressure cut-off switch (opens: 430 +/- 20 psi) (closes: 200 +/- 50 psi) (on rear of a/c compressor)
• A/c compressor nca clutch diode (in engine harness, approx 13 cm (5 in) from breakout toward a/c compressor high pressure cut-off switch)
• A/c compressor refrigerant pressure switch (body builder installed) (on a/c accumulator)
• A/c compressor relay (on engine firewall relay bracket, under battery junction block)
• A/c low pressure switch signal
• A/c request signal
• Breakout to maf sensor from inline resistor) s142
• Eng bat fuse 10 15a
• Gauges fuse 8 20a
• Hot at all times
• Hot in run & start
• I/p fuse block (body builder installed) (behind dash panel)
• Nca
• Nca a
• Pnk
• Provisions for body builder hvac
• Resistor (in engine harness, approx 23 cm (9 in) from breakout to maf & iat sensors)
• S125

5.7L

5.7L VIN R, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999

List of elements for 5.7L VIN R, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999:

• (at left rear of cylinder head) g114
• (in engine harness approximately 4 cm (2 in) from breakout for 36 pin in-line connector, left side of firewall towards grommet on same) s110
• (in engine harness approximately 7 cm (3 in) from throttle position sensor breakout toward an engine to fuel injector in-line harness connector: (12 pin, 4.3l vin w) (16 pin, 5.7l vin r) s138
• (in engine harness, approximately 11 cm (4 in) from 36 pin in-line connector breakout on left side of firewall, towards grommet on left side of firewall) s144
• (in engine harness, approximately 19 cm (8 in) from 36 pin in-line connector breakout on left side of firewall towards maf sensor) s132
• (left interior bulkhead near relay bracket) g202
• (on left side of radiator support) vehicle control module (vcm)
• 13 cm (5 in) from a/c compressor high pressure cut-off switch breakout) s124
• A/c compressor clutch (left side of engine)
• A/c compressor enable rly ctrl
• A/c compressor high pressure cut-off switch (opens: 430 +/- 20 psi) (closes: 200 +/- 50 psi) (on rear of a/c compressor)
• A/c compressor nca clutch diode (in engine harness, approx 13 cm (5 in) from breakout toward a/c compressor high pressure cut-off switch)
• A/c compressor refrigerant pressure switch (body builder installed) (on a/c accumulator)
• A/c compressor relay (on engine firewall relay bracket, under battery junction block)
• A/c low pressure switch signal
• A/c request signal
• Breakout to maf sensor from inline resistor) s142
• Eng bat fuse 10 15a
• Gauges fuse 8 20a
• Hot at all times
• Hot in run & start
• I/p fuse block (body builder installed) (behind dash panel)
• Nca
• Nca a
• Pnk
• Provisions for body builder hvac
• Resistor (in engine harness, approx 23 cm (9 in) from breakout to maf & iat sensors)
• S125

6.5L

6.5L VIN F, Manual A/C Wiring Diagram, Commercial Chassis for GMC Forward Control P3500 1999

List of elements for 6.5L VIN F, Manual A/C Wiring Diagram, Commercial Chassis for GMC Forward Control P3500 1999:

• (at rear of left cylinder head) g114
• (in engine harness on end of a/c compressor clutch diode, approximately 13 cm (5 in) from a/c compressor high pressure cut-off switch breakout) s124
• (in engine harness, approximately 11 cm (4 in) from breakout for 36 pin in-line connector in left side of firewall, toward a/c compressor connectors) s132
• (left interior bulkhead near relay bracket) g202
• A/c compressor clutch
• A/c compressor clutch diode
• A/c compressor high pressure cut-off switch (on rear of a/c compressor)
• A/c compressor refrigerant pressure switch (body builder installed) (on a/c accumulator)
• A/c compressor relay (on engine firewall relay bracket, under battery junction block)
• A/c compressor relay ctrl
• A/c request signal
• Approximately 4 cm (2 in) from starter motor breakout towards black black 15 pin harness in-line connector on frame rail) s118
• Eng bat fuse 10 15a
• Gauges fuse 8 20a
• Hot at all times
• Hot in run & start
• I/p fuse block (body builder installed) (behind dash panel)
• Nca
• Pnk
• Powertrain control module (pcm) (on left side of driver's island on relay bracket)
• Resistor nca (in engine harness, approximately 25 cm (10 in) from powertrain control module (pcm) connector c3)
• S125

6.5L VIN F, Manual A/C Wiring Diagram, Motor Home Chassis for GMC Forward Control P3500 1999

List of elements for 6.5L VIN F, Manual A/C Wiring Diagram, Motor Home Chassis for GMC Forward Control P3500 1999:

• (at right rear of cylinder head) g117
• (in breakout for a/c compressor clutch, 21 cm (9 in) from a/c compressor clutch connector) s123
• (in engine harness, 35 cm (13 in) from grommet left side of firewall in engine compartment) s115
• (mounted to top front of steering column support plate) g207
• A/c compressor clutch
• A/c compressor clutch diode
• A/c compressor high pressure cut-off switch (on rear of a/c compressor)
• A/c compressor refrigerant pressure switch (body builder installed) (on a/c accumulator)
• A/c compressor relay (on right side of driver's island)
• A/c compressor relay ctrl
• A/c request signal
• Eng bat fuse 10 15a
• Gauges fuse 8 20a
• Grommet toward 56-pin in-line connector on left side of dash) s235
• Hot at all times
• Hot in run & start
• I/p fuse block (body builder installed) (behind dash panel)
• Nca
• Pnk
• Powertrain control module (pcm) (on left side of driver's island on relay bracket)
• S122 (in breakout for a/c compressor clutch, 21 cm (9 in) from a/c compressor clutch connector)
• S168 (in engine harness, 4 cm (2 in) from breakout for 2 in-line connectors near battery junction block, left side of firewall)
• Stoplamp switch)

6.5L VIN Y, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999

List of elements for 6.5L VIN Y, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999:

• (in engine harness on end of a/c compressor clutch diode, approximately 13 cm (5 in) from a/c compressor high pressure cut-off switch breakout) s124
• (in engine harness, approximately 4 cm (2 in) from breakout for abs harness in-line connectors) s110
• (left interior bulkhead near relay bracket) g202
• A/c compressor clutch
• A/c compressor clutch diode
• A/c compressor high pressure cut-off switch (open: 430 +/- 20 psi) (close: 200 +/- 50 psi) (on rear of a/c compressor)
• A/c compressor refrigerant pressure switch (body builder installed) (on a/c accumulator)
• A/c compressor relay (on engine firewall relay bracket, under battery junction block)
• Eng-bat fuse 10 15a
• Hot at all times
• I/p fuse block (body builder installed) (behind dash panel)
• Nca
• S125

7.4L

7.4L VIN J, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999

List of elements for 7.4L VIN J, Manual A/C Wiring Diagram for GMC Forward Control P3500 1999:

• (at right rear of cylinder head) g117
• (body builder a/c controls)
• (in breakout for a/c compressor clutch, 21 cm (9 in) from a/c compressor clutch connector) s123
• (in breakout for vcm, 20 cm (8 in) from main engine harness) s132
• (in breakout for vcm, 20 cm (8 in) from main engine harness) s140
• (in engine harness, 35 cm (13 in) from grommet left side of firewall in engine compartment) s115
• (mounted to top front of steering column support plate) g207
• 1100 ohms (+/- 1%) 0.75 watt (in engine harness, 20 cm (8 in) from abs harness breakout)
• A/c compressor clutch
• A/c compressor enable rly ctrl
• A/c compressor high pressure cut-off switch (on rear of a/c compressor)
• A/c compressor refrigerant pressure switch (body builder installed) (open: 2-9 psi) (close: 22-32 psi) (on a/c accumulator)
• A/c compressor relay (on right side of driver's island)
• A/c request signal
• Diode
• Eng bat fuse 10 15a
• Gauges fuse 8 20a
• Grommet toward 56-pin in-line connector on left side of dash) s235
• Hot at all times
• Hot in run & start
• I/p fuse block (body builder installed) (behind dash panel)
• Low pressure cutout signal
• Nca
• Pnk
• S122 (in breakout for a/c compressor clutch, 21 cm (9 in) from a/c compressor clutch connector)
• S150
• Vehicle control module (vcm) (on top of radiator support)