GMC Forward Control P3500 (1985-1999) gry Wiring diagrams

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS HI IN A/T ISS LO IN A/T OUTPUT SPEED SENSOR ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE BUSS BAR GAUGES FUSE 8 DATA CLASS II DK BLU WIRE DK BLU/WHT 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 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 TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN TWISTED WIRE PAIR 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 A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS HI IN A/T ISS LO IN A/T OUTPUT SPEED SENSOR ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE BUSS BAR GAUGES FUSE 8 DATA CLASS II DK BLU WIRE DK BLU/WHT 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 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 TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN TWISTED WIRE PAIR 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 A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS HI IN A/T ISS LO IN A/T OUTPUT SPEED SENSOR ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE BUSS BAR GAUGES FUSE 8 DATA CLASS II DK BLU WIRE DK BLU/WHT 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 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 TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN TWISTED WIRE PAIR VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

7.4L 7.4L VIN J 6.5L VIN F A/C COMPRESSOR RELAY FAN CONTROL RELAY ALTERNATOR BATTERY BATTERY JUNCTION BLOCK (ON FORWARD LEFT SIDE OF THE BULKHEAD) BLK WIRE BLU WIRE BUSS BAR CONNECTOR FOR DOME LAMP DATA LINK CONNECTOR DIESEL ECM-BAT FUSE 6 ELECTRONIC BRAKE CONTROL MODULE ENG BAT FUSE 10 FAN CONTROL RELAY GLOW PLUG CONTROLLER FUEL PUMP RELAY FUSIBLE LINK FUSIBLE LINK (10 GA- FUSIBLE LINK (10 GA-RUST) FUSIBLE LINK (14 GA- FUSIBLE LINK (16 GA- FUSIBLE LINK (18 GA. FUSIBLE LINK (12 GA. GRY WIRE HAZARD FLASHER HEADLAMPS SWITCH HEADLAMPS SWITCH STOPLAMP SWITCH HORN DM FUSE 3 HORN RELAY I/P FUSE BLOCK (MOUNTED ON THE DASH) IGNITION SWITCH (DIAGRAM 2 OF 4) ORG/ WIRE PARK BRAKE PUMP MOTOR RELAY POWERTRAIN CONTROL MODULE VEHICLE CONTROL MODULE PWR CIRCUIT BREAKER 2 RED WIRE SEATBELT AND LAMPS ALARM MODULE SECONDARY BATTERY (DIESEL ONLY) STARTER MOTOR STARTER RELAY STOP-HAZ FUSE 11 TAIL LAMPS FUSE 7

1996 VFTC 7.4L VIN J ENGINE 7.4L VIN J ENGINES A/C COMPRESSOR RELAY GENERATOR AUX CIRCUIT BREAKER 13 BRN WIRE BUSS BAR CANADIAN MODELS CRUISE CONTROL MODULE CRUISE CONTROL SWITCH DAYTIME RUNNING LAMP RELAY DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE FROM ENG-1 FUSE (DIAGRAM 2 OF 4) FROM IGNITION SWITCH (DIAGRAM 2 OF 4) GAUGES FUSE 8 GRY WIRE HTR FUSE 1 I-3 FUSE 9 I/P FUSE BLOCK (MOUNTED ON THE DASH) INSTR LPS FUSE 16 INSTRUMENT CLUSTER INTERIOR LIGHTS SYSTEM (INSTRUMENT PANEL DIMMER SWITCH) NCA WIRE ORG/ WIRE PNK PNK WIRE PNK WIRE SEATBELT/ LAMPS ALARM MODULE DAYTIME RUNNING LAMP CONTROL MODULE TO ECM 1 FUSE DIAGRAM 3 OF 4) TORQUE CONVERTER CLUTCH AND STOP LAMPS SWITCH TURN B/U FUSE 5 TURN SIGNAL FLASHER VEHICLE CONTROL MODULE WIPER MOTOR BREAKOUT) PNK WIRE

1226 1225 TR SWITCH C TR SWITCH B TR SWITCH A 2-3 SHIFT SOLENOID VALVE 27 28 29 30 31 PPL 379 (OR 420) A/C SYSTEM A/T A/T M/T ANTILOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BATTERY BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT (OR PPL) WIRE BRN/WHT WIRE CLOSURE SIGNAL BOOST SENSOR SIG PRESS CTRL SOL VLV LO CLUTCH PEDAL POSITION SWITCH (TOP OF CLUTCH PEDAL SUPORT) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK/ PNK WIRE ECT SIGNAL GRN WIRE GRY WIRE LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/WHT WIRE ORG/ WIRE ORG/BLK WIRE PNK PNK PPL 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND ON RELAY BRACKET) PPL PPL APP 2 GROUND APP 1 GROUND APP 1 SIG PPL CKP SEN GRD A/C REQUEST SIG PPL PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID VALVE RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SENSOR GND SOLENOID VALVE 1-2 SHIFT SOLID STATE TAN WIRE TAN/BLK WIRE TCC PWM SOLENOID VALVE TCC/ABS BRAKE SW STOPLAMP SWITCH TIMING STEPPER MTR (HIGH) TIMING STEPPER MTR (LOW) TIMING STEPPER MTR (LOW) TRANSMISSION OUTPUT SPEED SENSOR (LEFT SIDE OF TRANS- MISSION, NEAR THE MIDDLE) TRANSMISSION SPEED INPUT TRANSMISSION TEMPERATURE SENSOR WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

27 28 29 30 31 PPL 5 VOLT REF ACCELERATOR PEDAL POSITION MODULE (ATTACHED TO ACCELERATOR PEDAL) APP 1 SENSOR APP 2 SENSOR APP 3 SENSOR BLK WIRE BLU WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT WIRE CLOSURE GRD CLOSURE SIGNAL DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE 12 ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR, ON LOWER CROSSMEMBER) ENG 1 FUSE 15 ENGINE SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUEL SOL CTRL FUEL SOL HIGH FUEL SOL LOW FUEL SOLE- NOID FUEL SOLENOID DRIVER (ON SIDE OF FUEL INJECTION PUMP) GRN WIRE GRY WIRE HIGH LOW HIGH RES SIG HOT AT ALL TIMES HOT IN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IGNITION TIMING STEPPER MOTOR (PART OF FUEL INJECTION PUMP) LOW HIGH LT BLU WIRE LT GRN WIRE LT PPL OPTICAL FUEL TEMPERATURE SENSOR (PART OF FUEL INJECTION PUMP ASSEMBLY) ORG/ WIRE ORG/BLK WIRE PNK PNK PPL 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE PPL PPL (ENG HARN, APPROX 32 CM FROM BREAKOUT FOR BATTERY JUNCTION BLOCK) PUMP CAM SIG RED WIRE RED/BLK WIRE RUN WIRE SENSOR GROUND STOP/HAZ FUSE 11 TAN WIRE TAN/BLK WIRE TORQUE CONVERTER CLUTCH (TCC), STOPLAMPS SWITCH (AT BRAKE PEDAL SUPPORT) TRANS FUSE 17 WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

A/T A/T M/T BLK WIRE BLK/WHT WIRE BLU WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-BAT FUSE 6 ENG BAT FUSE 10 FUEL HEATER (PART OF FUEL/WATER SEPARATOR) FUEL LIFT PUMP (INSIDE RIGHT FRAME RAIL) FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) FUEL PUMP RELAY (ON ENGINE FIREWALL RELAY BRACKET, UNDER BATTERY JUNCTION BLOCK) GAUGES FUSE 8 GRN WIRE GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK INDICATOR INSTRUMENT CLUSTER LT BLU WIRE LT GRN WIRE M/T MALFUNCTION INDICATOR LAMP (MIL) ORG/ WIRE PNK FEDERAL WIRE PNK PNK WIRE PNK WIRE RED WIRE SERVICE THROTTLE SOON INDICATOR SPEED METER TAN WIRE WAIT TO WASTEGATE SOLENOID (TOP LEFT REAR OF ENG) WATER IN FUEL INDICATOR WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

5-VOLT 6 9 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) BAROMETRIC PRESSURE (BARO) SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE EBCM ECM 1 FUSE 12 ECM-BAT FUSE 6 ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR, ON LOWER CROSSMEMBER) ENG SPEED SENS IN SENSOR RETURN TP SENS SIG ENGINE SPEED SENSOR (REAR OF INTAKE MANIFOLD, NEAR FUEL FILTER) GROUND GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) IGN FEED LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE PNK 3 4 5 6 7 8 WIRE PNK WIRE PPL PPL BRAKE PEDAL SW IN TCC PWM SOL CTRL PPL STOPLMP SW IN PPL/WHT WIRE PRESS CTRL SOL (LO) IGN FEED PNK WIRE PRESS CTRL SOL. HI RED WIRE RED/BLK WIRE REF RTN SENSOR SERVICE TRANS OUT SERIAL DATA SIG TAN WIRE TCM GROUND TCM GROUND SENSOR RETURN TFT SIG BARO PRESS SENS SIG THROTTLE POSITION SENSOR (TPS) (RIGHT SIDE OF FUEL INJECTION PUMP) TO GLOWPLUG CONTROLLER) VEHICLE SPEED SENSOR (VSS) (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED SIG SPEED SENSOR SPEED SENSOR VSS VSS INPUT VSS OUT VSS RTN VSS SIG WHT WIRE YEL/BLK WIRE

"WAIT TO START" GLOW PLUGS 1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID A/T AUTOMATIC TRANSMISSION (REAR OF ENGINE) BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK GRN WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 FUEL INJECTION PUMP SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUEL LIFT PUMP (ON INSIDE RIGHT FRAME RAIL) FUEL PUMP RELAY (ON ENGINE FIREWALL BRACKET, UNDER BATTERY JUNCTION BLOCK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE M/T NCA WIRE ORN/ PNK 3 4 5 6 7 8 WIRE PNK WIRE PRESSURE CONTROL SOLENOID RED WIRE RED/BLK WIRE SERVICE TRANS SPEEDO- METER TCC PWM SOLENOID TRANS FUSE 17 TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR TRANSMISSION RANGE (TR) PRESSURE SWITCH ASSEMBLY WATER IN FUEL WHT WIRE YEL WIRE YEL/BLK WIRE