GMC Forward Control P3500 (1985-1999) a/c request signal Wiring diagrams

A/C COMPRESSOR ENABLE RLY CTRL A/C COMPRESSOR, CLUTCH (LEFT SIDE OF ENGINE) A/C LOW PRESSURE SWITCH SIGNAL A/C REQUEST SIGNAL BLK WIRE BLU WIRE DK GRN WIRE ENG BAT FUSE 10 GAUGES FUSE 8 GRN WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BODY BUILDER INSTALLED) (BEHIND DASH PANEL) NCA WIRE ORG/ WIRE PNK WIRE PROVISIONS FOR BODY BUILDER HVAC WHT WIRE

A/C COMPRESSOR ENABLE RLY CTRL A/C COMPRESSOR, CLUTCH (LEFT SIDE OF ENGINE) A/C LOW PRESSURE SWITCH SIGNAL A/C REQUEST SIGNAL BLK WIRE BLU WIRE DK GRN WIRE ENG BAT FUSE 10 GAUGES FUSE 8 GRN WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BODY BUILDER INSTALLED) (BEHIND DASH PANEL) NCA WIRE ORG/ WIRE PNK WIRE PROVISIONS FOR BODY BUILDER HVAC WHT WIRE

A/C COMPRESSOR CLUTCH DIODE A/C COMPRESSOR CLUTCH A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) A/C COMPRESSOR RELAY CTRL A/C REQUEST SIGNAL BLK WIRE DK GRN WIRE DK GRN/WHT (OR NCA) WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BODY BUILDER INSTALLED) (BEHIND DASH PANEL) LT BLU WIRE NCA WIRE ORG/ WIRE PNK WIRE PROVISION FOR BODY BUILDER BLUNT CUT WHT WIRE

A/C COMPRESSOR CLUTCH DIODE A/C COMPRESSOR CLUTCH A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) A/C COMPRESSOR RELAY (ON RIGHT SIDE OF DRIVER'S ISLAND) A/C COMPRESSOR RELAY CTRL A/C REQUEST SIGNAL BLK WIRE DK GRN WIRE DK GRN/WHT (OR NCA) WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BODY BUILDER INSTALLED) (BEHIND DASH PANEL) LT BLU WIRE NCA WIRE ORG/ WIRE PNK WIRE PROVISION FOR BODY BUILDER BLUNT CUT WHT WIRE

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 RELAY (ON RIGHT SIDE OF DRIVER'S ISLAND) A/C REQUEST SIGNAL BLK WIRE BLU WIRE DIODE DK GRN WIRE ENG BAT FUSE 10 GAUGES FUSE 8 HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BODY BUILDER INSTALLED) (BEHIND DASH PANEL) LOW PRESSURE CUTOUT SIGNAL NCA WIRE ORG/ WIRE PNK WIRE VEHICLE CONTROL MODULE (VCM) (ON TOP OF RADIATOR SUPPORT) WHT WIRE

1 2 3 4 5 6 7 8 PNK PNK WIRE A/C COMP CYL SW A/C REQUEST SIGNAL AIR CONDITIONING SYSTEM AUX ELECT COOLING FAN BRAKE SIGNAL SERIAL DATA PPL PPL B(+) BATTERY FEED RANGE SIGNAL B RANGE SIGNAL A BLK RED/ WIRE BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE COOLING FANS SYSTEM CRUISE CONTROL MODULE (ON RADIATOR SUPPORT BRACKET) CRUISE CTRL ENGAGED CRUISE ENGAGED SIG CTRL EST CYLINDER 1 CYLINDER 4 CYLINDER 5 CYLINDER 3 CYLINDER 6 CYLINDER 7 CYLINDER 2 CYLINDER 8 DISTRIBUTOR DK BLU WIRE DK GRN WIRE DK GRN/ WHT WIRE DK GRN/WHT WIRE ECM B FUSE 6 EGR VALVE FEED EGR VLV CTRL FUEL PMP RLY CTRL 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) GRN WIRE GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK IGN FEED IGNITION COIL (ON BRACKET AT REAR OF INTAKE PLENUM) IGNITION CONTROL MODULE (ON BRACKET AT REAR OF INTAKE PLENUM) LT BLU/BLK WIRE LT BLU/WHT WIRE ORG/ WIRE PCS HIGH INPUT SPEED SENS LOW INPUT SPEED SENS HIGH IC CNTRL PCS LOW VCM GROUND VCM GROUND SENS GROUND PNK 16 17 18 19 20 21 WIRE PNK 22 23 WIRE PNK IGN FEED WIRE PNK WIRE PPL PPL ANTI-LOCK BRAKES SYSTEM PPL PPL DATA LINK CONNECTOR (DLC) (BELOW DASH, NEAR STEERING COLUMN) 4 5 PPL FUEL LEVEL MODULE A/C REC PPL TCC/STOPLAMP INPUT RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SIGNAL TIMING CTRL ELEC SPK SPARK PLUGS SPEED SENSOR INPUT TCC STOPLAMP SWITCH (OPENS W/BRAKE DEPRESSED) (AT BRAKE PEDAL SUPPORT) VSS OUTPUT SIGNAL VSS OUTPUT SIGNAL CHECK ENGINE LP CTRL WHT WIRE WHT/ BLU WIRE WHT/BLK WIRE

1 2 3 4 5 6 7 8 PNK PNK WIRE A/C COMP CYL SW A/C REQUEST SIGNAL AIR CONDITIONING SYSTEM ANTI-LOCK BRAKES SYSTEM PPL AUX ELECT COOLING FAN BRAKE SIGNAL SERIAL DATA PPL PPL 420 1807 B(+) BATTERY FEED RANGE SIGNAL B RANGE SIGNAL A 1225 1224 PNK WIRE BLK RED/ WIRE BLK WIRE BLK/WHT WIRE BLU/ WHT WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE COOLING FANS SYSTEM CRUISE CONTROL MODULE (ON RADIATOR SUPPORT BRACKET) CRUISE CTRL ENGAGED CRUISE ENGAGED SIG CYLINDER 1 CYLINDER 4 CYLINDER 5 CYLINDER 3 CYLINDER 6 CYLINDER 7 CYLINDER 2 CYLINDER 8 DISTRIBUTOR DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM B FUSE 6 EGR VALVE FEED EGR VLV CTRL ELEC SPK TIMING CTRL SIGNAL EST CTRL FUEL PMP RLY CTRL 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (LEFT SIDE OF ENGINE COMPT) GRN WIRE GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK IGN FEED IGNITION COIL (ON BRACKET AT REAR OF INTAKE PLENUM) IGNITION COIL MODULE (ON BRACKET AT REAR OF INTAKE PLENUM) LT BLU/BLK WIRE LT BLU/WHT WIRE ORG/ WIRE PCS HIGH INPUT SPEED SENS LOW INPUT SPEED SENS HIGH IC CNTRL PCS LOW GROUND GROUND SENS GROUND PNK 22 23 WIRE PNK IGN FEED WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (DLC) (BELOW DASH, NEAR STEERING COLUMN) 4 5 PPL FUEL LEVEL MODULE A/C REC PPL TCC/STOPLAMP INPUT RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SPARK PLUGS SPEED SENSOR INPUT VEHICLE CONTROL MODULE (VCM) (ON CENTER FRONT OF ENGINE COMPARTMENT) VSS OUTPUT SIGNAL VSS OUTPUT SIGNAL CHECK ENGINE LP CTRL 389 419 WHT DK GRN/ WIRE WHT WIRE WHT/BLK WIRE