GMC Forward Control P3500 (1985-1999) tan/wht Wiring diagrams

A/C COMPRESSOR A/C COMPRESSOR PRESSURE CYCLING SWITCH BATTERY BLK WIRE BLK/ WHT WIRE BLK/WHT WIRE BLOWER MOTOR BLOWER RELAY BRAKE SHIFT INTERLOCK RELAY BRAKE/ TRANSMISSION SHIFT INTERLOCK SOLENOID VEHICLE SPEED SENSOR BUFFER BUS BAR GROUND CANADA ONLY CIGARETTE LIGHTER CRUISE CONTROL MODULE DATA LINK CONN- ECTOR FUEL PUMP RELAY DAYTIME RUNNING LAMPS MODULE DAYTIME RUNNING LAMPS RELAY DK GRN WIRE EGR ELECTRONIC VACUUM REGULATOR VALVE SOLENOID FLOW SWITCH (BRAKES) FUEL PUMP HEATER CONTROL LAMP IN LINE DIODE INSTRUMENT CLUSTER LEFT HIGH BEAM HEADLAMP LEFT HORN LEFT LOW BEAM HEADLAMP LEFT PARK AND TURN LAMP LEFT PARK LAMP LEFT SIDE MARKER LAMP LEFT TAIL STOP AND TURN LAMP LICENSE LAMP GROUND (FROM BODY BUILDER) POWER DOOR LOCK RELAY POWERTRAIN CONTROL MODULE (PCM) PROVISIONS FOR CLEARANCE LAMPS LEFT POWER WINDOW SWITCH RADIO RIGHT HIGH BEAM HEADLAMP RIGHT HORN RIGHT LOW BEAM HEADLAMP RIGHT PARK AND TURN LAMP RIGHT PARK LAMP SAFETY BELT RETRACTOR SWITCH AUDIO ALARM MODULE TAN WIRE TAN/WHT WIRE WINDSHIELD WASHER PUMP LIGHT SWITCH WINDSHIELD WIPER MOTOR MODULE

BLK WIRE BRN WIRE DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (IN I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (IN I/P HARNESS) DK BLU/WHT WIRE DK GRN/YEL WIRE FUSE BLOCK GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HORN/DM FUSE HOT AT ALL TIMES HOT IN RUN HTR FUSE INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PROVISIONS FOR FOG LAMPS RIGHT HEADLAMP ASSEMBLY TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

BLK WIRE BLU WIRE BRN WIRE DAYTIME RUNNING LAMP CUTOFF RELAY DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (IN I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (IN I/P HARNESS) DK BLU/WHT WIRE DK GRN/YEL WIRE GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HORN/DM FUSE HOT AT ALL TIMES HOT IN RUN OR START FUSE BLOCK HTR FUSE INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LEFT LOWER HEADLAMP (W/ HPR) LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PROVISIONS FOR FOG LAMPS RIGHT HEADLAMP ASSEMBLY RIGHT LOWER HEADLAMP (W/ HPR) TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

ABS IND. ACCY ACCY ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRAKE IND BRAKE PRESSURE DIFFERENTIAL SWITCH (INTERNAL TO ELECTRONIC BRAKE CONROL MODULE) BRN/WHT WIRE CHECK GAUGES IND COOLANT TEMPERATURE GAUGE DIESEL DIODE NETWORK (DASH HARN, DK BLU WIRE DK GRN WIRE DOOR AJAR IND DRL IND ECM 1 FUSE 12 ELECTRONIC BRAKE CONTROL MODULE (EBCM) (BELOW RADIATOR, ON LOWER CROSSMEMBER) ENG 1 FUSE 15 ENGINE CONTROLS OR STARTING/CHARGING SYSTEM ENGINE CONTROLS SYSTEM ENGINE CONTROLS SYSTEM ENGINE CONTROLS SYSTEM TRANSMISSIONS SYSTEM ENGINE COOLANT LEVEL SWITCH (ON LOWER LEFT END OF RADIATOR SURGE TANK) FOOT BRAKE (PARK BRAKE APPLY OPPTION) FUEL GAUGE FUEL SENDER (ON TOP OF FUEL TANK) GAS GAUGES FUSE 8 GRY WIRE GRY/BLK WIRE HAND BRAKE HEADLIGHTS SYSTEM HI-BEAM IND HOT IN RUN OR START I/P FUSE BLOCK I/P FUSE BLOCK (BODY BUILDER INSTALLED) I/P FUSE BLOCK) INSTRUMENT CLUSTER IGNITION SWITCH ILLUMINATION IN-LINE CONNECTOR PROVISIONS FOR BODY BUILDER INTERIOR LIGHTS SYSTEM WARNING SYSTEMS LEFT TURN IND LOCK LOCK OFF OFF LOW COOLANT IND LT BLU WIRE LT BLU/BLK WIRE LT GRN (OR WHT) WIRE LT GRN WIRE MALFUNCTION IND (MIL) (SERVICE ENGINE SOON IND) NCA WIRE OIL PRESSURE GAUGE PNK 4 13 WIRE PNK WIRE PPL PPL DIESEL PPL GAS PPL RIGHT TURN IND RUN WIRE SEAT BELT IND SERVICE THROTTLE SOON IND SPEEDOMETER TACHOMETER TAN WIRE TAN/WHT WIRE TRANS IND. VEHICLE CONTROL MODULE (ON LEFT SIDE OF RADIATOR SUPPORT) VOLTMETER VSS CALIBRATOR (LEFT SIDE OF DRIVER'S ISLAND, UNDER RELAY BRACKET) W/ DRL W/O DRL WAIT TO START IND WATER IN FUEL IND WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

0.5 WATT) 1995 VFTC BLK WIRE BLK/YEL WIRE BRAKE IND BRAKE PRESSURE WARNING SWITCH (ON LEFT FRAME RAIL) IGNITION SWITCH BRAKE WARNING ALARM BUZZER (BEHIND LEFT SIDE OF I/P, NEAR FUSE BLOCK) BRN WIRE BRN/WHT WIRE COOLANT TEMP GAUGE CRUISE CONTROL SYSTEM DAYTIME RUNNING LAMPS IND DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) DAYTIME RUNNING LAMPS RELAY (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) DK BLU WIRE DK GRN WIRE DK GRN/YEL WIRE ELECTRONIC DELAY MODULE (BEHIND LEFT SIDE OF I/P, ON PARK BRAKE SUPPORT BRACKET) ENGINE CONTROLS SYSTEM FLOW SWITCH (NEAR POWER STEERING PUMP) FUEL GAUGE FUSE BLOCK GAGES FUSE GRY WIRE HEADLIGHTS SYSTEM HI-BEAM IND HOT IN RUN OR START HYDRO-BOOST PRESSURE WARNING SWITCH (NEAR MASTER CYLINDER) ILLUM LAMP ILLUM. LAMPS IN-LINE DIODE (BEHIND LEFT SIDE OF I/P, ABOVE FUSE BLOCK) IN-LINE DIODE (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) INSTRUMENT CLUSTER LEFT TURN IND LOW COOLANT IND LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MAL- FUNCTION IND OIL PRESS GAUGE PARK BRAKE WARNING SWITCH PNK PNK WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (UNDER DRIVER'S SEAT) PPL RESISTOR RIGHT TURN IND SAFETY BELT IND SPEED- OMETER TAN WIRE TAN/WHT WIRE VEHICLE SPEED SENSOR (REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND LEFT SIDE OF I/P) VOLT- METER W/ DRL W/ DRL PPL PPL W/O DRL WARNING SYSTEMS WHT WIRE YEL WIRE

1995 VFTC ACCY ALT FUSE AUDIO ALARM MODULE CONVENIENCE CENTER BLK WIRE BRAKE IND BRAKE PRESSURE WARNING SWITCH (NEAR MASTER CYLINDER) BRAKE WARNING ALARM BUZZER MODULE (BRAKE WARNING HARNESS) BRN WIRE BRN/WHT WIRE BULB TEST COOLANT TEMP GAUGE DAYTIME RUNNING LAMPS MODULE (TOP RIGHT SIDE OF SHIPPING HARNESS) DAYTIME RUNNING LAMPS RELAY DAYTIME RUNNING LIGHTS IND DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/YEL WIRE ELECTRONIC DELAY MODULE (BRAKE WARNING HARNESS) ENGINE CONTROLS SYSTEM ENGINE COOLANT TEMPERATURE SENDER (LEFT FRONT OF ENGINE) FLOW SWITCH (BRAKE BOOSTER) FUEL GAUGE FUEL PUMP OIL PRESSURE SWITCH, SENDER (TOP REAR OF ENGINE) FUEL PUMP, SENDER (IN FUEL TANK) FUSE BLOCK GAUGES FUSE GRY WIRE HEAD- LIGHTS SYSTEM HEADLIGHTS SYSTEM HI-BEAM IND HOT IN RUN OR START HOT IN RUN, BULB TEST OR START HYDRO-BOOST PRESSURE WARNING SWITCH (BRAKE WARNING HARNESS) I/P GROUND (AT LEFT SHIPPING PANEL) IGNITION SWITCH ILLUM. LAMPS INSTRUMENT CLUSTER LEFT TURN IND LOCK OFF LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MAL- FUNCTION IND NCA WIRE OIL PRESS GAUGE PARK BRAKE IND PARK BRAKE WARNING SWITCH (PARK BRAKE PEDAL BRACKET) PNK PPL WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF I/P, BEHIND SHIPPING PANEL) PPL RESISTOR RIGHT TURN IND. SAFETY BELT IND. RUN WIRE SHUNT SPEED- OMETER TAN WIRE TAN/WHT WIRE VEHICLE SPEED SENSOR (REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (LEFT SIDE OF SHIPPING PANEL) VOLT- METER W/ DRL W/O DRL WHT WIRE YEL WIRE

ACC RADIO FUSE ACCY BATTERY JUNCTION BLOCK BLK WIRE BODY BUILDER'S DAYTIME RUNNING LAMPS JUNCTION BLOCK RELAY BRAKE WARNING SYSTEM (WARNING SYSTEMS) BRN WIRE BULB TEST CLUTCH DAYTIME RUNNING LAMPS MODULE WIPER MOTOR DK GRN WIRE ECM BAT FUSE FROM PANEL DIMMER SWITCH FROM PARK BRAKE WARNING SWITCH FUEL CYCLE MODULE DAYTIME RUNNING LAMPS RELAY FUEL PUMP RELAY, FUEL PUMP/ OIL PRESSURE SWITCH FUSE BLOCK FUSE BLOCK, GLOW PLUG CONTROLLER FUSIBLE FUSIBLE LINK E GAGES FUSE SHUNT GENERATOR GRY WIRE HAZARD FLASHER HEADLIGHT SWITCH ASSEMBLY HORN RELAY HORN/DM TAIL LPS FUSE FUSE HTR FUSE IGNITION SWITCH INSTR LPS FUSE INSTRUMENT TRANSMISSION CLUSTER RANGE INDICATOR LAMP LINK A LINK B LINK C LINK D LINK F LOCK LOCK OFF OFF ORG/ WIRE PCM PNK WIRE PNK/WHT WIRE POWERTRAIN CONTROL MODULE PPL RED WIRE RIGHT FRONT BATTERY LEFT REAR BATTERY RUN WIRE SHUNT STARTER RELAY STARTER SOLENOID STOP- HZ FUSE STOPLAMP SWITCH SWITCH TAN/WHT WIRE TO GLOW PLUG CONTROLLER W/ AUTO TRANSMISSION W/ MANUAL TRANSMISSION ONLY PPL WHT WIRE WIPER FUSE WIPER SWITCH

1995 VFTC ACC RADIO FUSE ACCY ACCY BULB TEST LOCK OFF ALT, ECM-CRANK, TURN-B/U, TRANS AND INJ FUSES BATT BUS BATTERY BATTERY JUNCTION BLOCK BLK WIRE BLK/RED WIRE BODY BUILDER'S JUNCTION BLOCK BRAKE WARNING SYSTEM (WARNING SYSTEMS) BRN WIRE BULB TEST CLUTCH DAYTIME RUNNING LAMPS HORN RELAY DAYTIME RUNNING LAMPS RELAY DAYTIME RUNNING LAMPS MODULE DK GRN WIRE ECM-BAT FUSE ACC BUS EXHAUST GAS REGULATOR SOLENOID VALVE GENERATOR FUEL CYCLE MODULE FUEL PUMP RELAY, FUEL PUMP/ OIL PRESSURE SWITCH FUSE BLOCK FUSIBLE LINK A FUSIBLE LINK C FUSIBLE LINK D GAGES FUSE SHUNT GENERATOR GRY WIRE HAZARD FLASHER HEADLIGHT SWITCH ASSEMBLY HEATED OXYGEN SENSOR (VIN Z) HORN/DM FUSE HTR FUSE HTR BUS IGNITION SWITCH INSTR-LPS CRANK FUSE FUSE LINK B FUSIBLE LOCK LOCK OFF OFF ORG/ WIRE PARK BRAKE WARNING SWITCH PCM PNK WIRE PNK/WHT WIRE POWERTRAIN CONTROL MODULE PPL RED WIRE RELAY RUN WIRE SHUNT STARTER SOLENOID STOP- HZ FUSE STOPLAMP SWITCH SWITCH PANEL DIMMER SWITCH (INTERIOR LIGHTS SYSTEM) TAIL LPS FUSE TAN/WHT WIRE TRANSMISSION CONTROL MODULE W/ AUTO TRANS WHT WIRE WIPER FUSE WIPER MOTOR WIPER SWITCH WITH MANUAL TRANSMISSION ONLY

5.7L 7.4L 7.4L ONLY AIR CONDITION- ING SYSTEM BLK WIRE BLK/RED WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE DIAGNOSTIC TEST TP SENSOR SIGNAL INJECTOR 1 CONTROL DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK GRN/YEL WIRE ECM I FUSE ECT SIGNAL EGR CONTROL EVAPORATIVE CANISTER PURGE CONTROL SOLENOID (TOP RIGHT SIDE OF ENGINE) EXHAUST GAS RECIRCULATION VALVE SOLENOID (TOP RIGHT SIDE OF ENGINE) FUEL PUMP RELAY CTRL PCS LOW FUEL PUMP SIGNAL MAP SIGNAL FUSE BLOCK GRY WIRE GRY/RED WIRE HOT IN RUN, BULB TEST OR START IC BYPASS SENSOR GROUND SENSOR GROUND TFT SIGNAL 470 455 PPL IDLE AIR CONTROL ACTUATOR (TOP REAR OF ENGINE) IDLE SPEED ACTUATOR CONTROL SOLENOID (NO LOCATION AVAILABLE) KNOCK SIGNAL EGR PINTLE POSITION SIGNAL LINEAR EGR VACUUM REGULATOR SOLENOID VALVE (TOP FRONT OF ENGINE) LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) OXYGEN SENSOR GROUND PNK 22 23 WIRE PNK RANGE SIGNAL A INPUT SPEED SIGNAL HIGH INPUT SPEED SIGNAL LOW WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PPL 20 21 PPL/WHT WIRE RANGE SIGNAL B RANGE SIGNAL C MIL CONTROL RED WIRE RED/BLK WIRE TAN WIRE TAN/BLK WIRE TAN/WHT WIRE THROTTLE BODY FUEL INJECTOR #1 (TOP OF THROTTLE BODY UNIT) THROTTLE BODY FUEL INJECTOR #2 (TOP OF THROTTLE BODY UNIT) TRANSMISSION INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

5.7L 7.4L 7.4L ONLY AIR CONDITION- ING SYSTEM BLK WIRE BLK/RED WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE DIAGNOSTIC TEST TP SENSOR SIGNAL INJECTOR 1 CONTROL DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK GRN/YEL WIRE ECM BAT FUSE ECM I FUSE ECT SIGNAL EGR CONTROL EVAPORATIVE CANISTER PURGE CONTROL SOLENOID (TOP RIGHT SIDE OF ENGINE) EXHAUST GAS RECIRCULATION VALVE SOLENOID (TOP RIGHT SIDE OF ENGINE) FUEL PUMP RELAY CTRL PCS LOW FUEL PUMP SIGNAL MAP SIGNAL FUSE BLOCK GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START IC BYPASS SENSOR GROUND SENSOR GROUND TFT SIGNAL 470 455 PPL IDLE AIR CONTROL ACTUATOR (TOP REAR OF ENGINE) IDLE SPEED ACTUATOR CONTROL SOLENOID (NO LOCATION AVAILABLE) KNOCK SIGNAL EGR PINTLE POSITION SIGNAL LINEAR EGR VACUUM REGULATOR SOLENOID VALVE (TOP FRONT OF ENGINE) LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) OXYGEN SENSOR GROUND PNK 22 23 WIRE PNK RANGE SIGNAL A INPUT SPEED SIGNAL HIGH INPUT SPEED SIGNAL LOW WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PPL 20 21 PPL/WHT WIRE RANGE SIGNAL B RANGE SIGNAL C MIL CONTROL RED WIRE RED/BLK WIRE TAN WIRE TAN/BLK WIRE TAN/WHT WIRE THROTTLE BODY FUEL INJECTOR #1 (TOP OF THROTTLE BODY UNIT) THROTTLE BODY FUEL INJECTOR #2 (TOP OF THROTTLE BODY UNIT) TRANSMISSION INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE