GMC Forward Control P3500 (1985-1999) lt grn Wiring diagrams

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 4.3L (VIN W), 5.7L (VIN R) A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T FLUID PRESSURE MANUAL VALVE POSITION SWITCH A/T ISS HI IN A/T ISS LO IN ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE, CRUISE CONTROL MODULE ENGINE CONTROLS SYSTEM FUEL INJECTORS (ENGINE CONTROLS SYSTEM) FUEL PUMP RELAY, SWITCH GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (PARTIAL) (BELOW DASH NEAR STEERING COLUMN) PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN SERVICE ENGINE SOON INDICATOR TCC PWM SOL TCC PWM SOLENOID TCC/ STOP LAMPS SWITCH THROTTLE POSITION SENSOR (ON THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS TEMP SIG IN VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 4.3L (VIN W), 5.7L (VIN R) A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T FLUID PRESSURE MANUAL VALVE POSITION SWITCH A/T ISS HI IN A/T ISS LO IN ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE, CRUISE CONTROL MODULE ENGINE CONTROLS SYSTEM FUEL INJECTORS (ENGINE CONTROLS SYSTEM) FUEL PUMP RELAY, SWITCH GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (PARTIAL) (BELOW DASH NEAR STEERING COLUMN) PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN SERVICE ENGINE SOON INDICATOR TCC PWM SOL TCC PWM SOLENOID TCC/ STOP LAMPS SWITCH THROTTLE POSITION SENSOR (ON THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS TEMP SIG IN VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 3-2 SHIFT SOL 3-2 SHIFT SOLENOID A/C COMPRESSOR RELAY GENERATOR A/T FLUID PRESSURE MANUAL VALVE POSITION SWITCH A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS SENS HI IN A/T ISS SENS LO IN A/T OUTPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) ACCELERATOR PEDAL POSITION MODULE (ATTACHED TO ACCELERATOR PEDAL) APP 1 SIGNAL IN APP 2 SIGNAL IN APP 3 SIGNAL IN AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SWITCH IN BRN WIRE BRN/WHT WIRE CLASS II DATA DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENSOR IN ELECTRONIC BRAKE CONTROL MODULE ENGINE COOLANT TEMPERATURE SENSOR (TOP FRONT OF ENGINE) FUEL PUMP RELAY, ENGINE OIL PRESSURE INDICATOR SENSOR GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE OSS HI IN OSS LO IN OSS OUT PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL PPL PPL/WHT WIRE PRESS CTRL HI SOLENOID RED WIRE RED/BLK WIRE SENSOR GROUND SERVICE ENGINE SOON INDICATOR STOP-HAZ FUSE 11 STOPLAMP SWITCH IN TAN WIRE TFT SENSOR IN TORQUE CONVERTER CLUTCH, STOPLAMP SWITCH TRANS FLUID TEMP SENSOR TRANS RANGE "A" TRANS RANGE "B" TRANS RANGE "C" TRANSMISSION FUSE 17 VEHICLE SPEED SENSOR BUFFER VEHICLE SPEED SENSOR CALIBRATOR (LEFT SIDE OF DRIVER'S ISLAND) VSS LO IN VSS OUT WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

2-3 SHIFT SOL CTRL 1-2 SHIFT SOL CTRL DIAGNOSTIC TEST 9 6 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) A/T INPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T OUTPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) AUTOMATIC TRANSMISSION BAROMETRIC PRESSURE SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SIGNAL TCC PWM CONTROL BRN WIRE DK BLU WIRE DRL MODULE, DRL RELAY, GENERATOR ECM 1 FUSE 12 ECM-BAT FUSE 6 ELECTRONIC BRAKE CONTROL MODULE ENGINE OIL PRESSURE INDICATOR SENSOR, FUEL PUMP RELAY ENGINE SPEED SENSOR (REAR OF INTAKE MANIFOLD) ENGINE SPEED SIGNAL SENSOR GROUND TP SENSOR INPUT FUEL INJECTION PUMP SHUTOFF SOLENOID,, FUEL PUMP RELAY GAUGES FUSE 8 GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGN BUSS INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OSS INPUTS OUT PCS HI PCS LO IGNITION PNK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C RED WIRE RED/BLK WIRE RUN WIRE SERVICE TRANS IND SERIAL DATA SERVICE TRANSMISSION INDICATOR SYSTEM GROUND SYSTEM GROUND SENSOR GROUND 5 VOLTS REF TAN WIRE TCC PWM SOL 1-2 SHIFT SOL 2-3 SHIFT SOL THROTTLE POSITION SENSOR (RIGHT SIDE OF FUEL INJECTION PUMP) TORQUE CONVERTER CLUTCH, STOPLAMP SWITCH TRANS FLUID TEMP SIG BARO SENSOR INPUT TRANS FUSE 17 TRANSMISSION CONTROL MODULE (LEFT SIDE OF DRIVER'S ISLAND) TRANSMISSION TEMPERATURE SENSOR VEHICLE SPEED INPUT INPUT SPEED SENS LO INPUT SPEED SENS HI VEHICLE SPEED SENSOR CALIBRATOR VEHICLE SPD OUTPUT WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 4.3L (VIN W), 5.7L (VIN R) A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T FLUID PRESSURE MANUAL VALVE POSITION SWITCH A/T ISS HI IN A/T ISS LO IN ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE, CRUISE CONTROL MODULE ENGINE CONTROLS SYSTEM FUEL INJECTORS (ENGINE CONTROLS SYSTEM) FUEL PUMP RELAY, SWITCH GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (PARTIAL) (BELOW DASH NEAR STEERING COLUMN) PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN SERVICE ENGINE SOON INDICATOR TCC PWM SOL TCC PWM SOLENOID TCC/ STOP LAMPS SWITCH THROTTLE POSITION SENSOR (ON THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS TEMP SIG IN VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

"SERV THROTTLE SOON" IND A/C ENABLE GROUND GROUND 451 551 A/C SYSTEM ANTILOCK BRAKES SYSTEM BATTERY BATTERY WASTEGATE SOL CTRL BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CALIFORNIA CALIFORNIA DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ESO CTRL FUSIBLE LINK FUSIBLE LINK (22 GA-RUST) FUSIBLE LINKS GLOW PLUG CONTROLLER (LEFT REAR OF ENG, NEAR FIREWALL) GRD IGNITION GLOW PLUG SIG RLY CTRL PNK WIRE HOT AT ALL TIMES LEFT BANK GLOW PLUGS LT BLU WIRE LT GRN WIRE NCA WIRE ORG/ WIRE PNK IGNITION RLY CTRL GRD BATTERY GLOW PLUG OUT WIRE PNK PNK 439 439 IGNITION IGNITION BATTERY MIL IND CTRL WIRE PNK PNK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND ON RELAY BRACKET) PPL PPL GLOW PLUG OUT GLOW PLUG OUT GLOW PLUG OUT GLOW PLUG OUT RED WIRE RIGHT BANK GLOW PLUGS TAN WIRE WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

2 3 PPL 2-3 SHIFT SOL CTRL ANTI-LOCK BRAKES SYSTEM BANK 2 SENSOR 1 (ON RIGHT EXHAUST DOWN PIPE, BEFORE CATALYTIC CONVERTER) BLK LT GRN/ WIRE BLK WIRE BLK/WHT WIRE BLU/BLK WIRE BRN WIRE BRN/WHT WIRE CAMSHAFT POSITION SENSOR (INTERNAL TO DISTRIBUTOR) CMP LOW FUEL GAUGE PPL DK BLU WIRE DK BLU/WHT WIRE FEED IGN GRN/BLK WIRE HEATED OXYGEN KS SIGNAL LEFT KNOCK SENSOR (ON LOWER LEFT SIDE OF ENGINE) LT BLU/ BLK WIRE LT BLU/ WHT WIRE LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WHT/ WIRE LT GRN WIRE LT GRN/ BLK WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE MAP SIGNAL IAT SIGNAL ECT SIGNAL NCA WIRE PNK 8 9 10 WIRE PNK IGN FEED SENS RTN SENS SIG WIRE PNK WIRE PNK/BLK WIRE PPL PPL CKP LOW VSS LOW VSS SIGNAL PPL PPL PPL/ WHT WIRE PPL/WHT WIRE RED/BLK WIRE RIGHT KNOCK SENSOR (ON LOWER RIGHT SIDE OF ENGINE) SENSOR RTN SIGNAL SENSOR T/P SIGNAL TAN WIRE TAN/WHT WIRE TFT SIGNAL MAF SIGNAL IAC HIGH IAC LOW INJECTOR 4 CTRL INJECTOR 3 CTRL VSS YEL WIRE YEL/BLK WIRE

2 3 PPL AUTOMATIC TRANSMISSION BANK 1 SENSOR 1 (ON LEFT EXHAUST SYSTEM DOWN PIPE, BEFORE CATALYTIC CONVERTER) BANK 1 SENSOR 2 (ON LEFT EXHAUST SYSTEM, AFTER CATALYTIC CONVERTER) BANK 2 SENSOR 2 (ON RIGHT EXHAUST SYSTEM AFTER CATALYTIC CONVERTER) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/BLK WIRE BREAKOUT) BRN WIRE DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE 12 ENG 1 FUSE 15 EXHAUST GAS RECIRCULATION VALVE SOLENOID (TOP LEFT SIDE OF ENG) FLUID TEMPERATURE SENSOR (INTERNAL) FORCE MOTOR FUEL INJ 1 FUEL INJ 2 FUEL INJ 4 FUEL INJ 5 FUEL INJ 3 FUEL INJ 6 FUEL INJ 7 FUEL INJ 8 GRN WIRE GRN/BLK WIRE GRY WIRE HEATED OXYGEN HOT IN RUN AND START I/P FUSE BLOCK IGNITION INTAKE AIR TEMP SENSOR (MOUNTED IN FRESH AIR INTAKE BEHIND AIR FILTER BOX) LT BLU/ WHT WIRE LT BLU/WHT WIRE LT GRN WIRE NCA WIRE PNK 8 9 10 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE PPL/ WHT WIRE PPL/WHT WIRE PRESSURE PRESSURE SWITCH RED WIRE RED/BLK WIRE SOLENOID SOLENOID 1-2 SOLENOID 2-3 SWITCH TAN WIRE TAN/ WHT WIRE TAN/WHT WIRE TCC WHT PPL/ WIRE WHT WIRE YEL WIRE YEL/BLK WIRE

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT FOR CRUISE CONTROL MODULE, TOWARD RELAYS) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE SENSOR (ON TOP FRONT OF ENGINE) FUEL GAUGE FUEL PUMP MODULE (ON TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK IN PCM BREAKOUT, 20 CM FROM MAIN HARNESS TOWARD FUEL PUMP RELAY) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP (MIL) "SERVICE ENGINE SOON" MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP CENTER FRONT OF ENGINE) MASS AIR FLOW SENSOR (RIGHT FRONT OF ENGINE COMP, ON AIR INTAKE ASSEMBLY) NCA WIRE ORG/ WIRE PNK 16 17 18 19 20 21 WIRE PNK 22 23 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE RED WIRE RED/BLK WIRE SPEED METER TACH THROTTLE POSITION SENSOR (ON THROTTLE BODY, TOP OF ENGINE) TRANS FUSE 17 WHT WIRE YEL WIRE