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

** (RIGHT FRAME RAIL, NEAR BATTERY) 1995 VFTC AUDIO ALARM MODULE AUTO APPLY PARK BRAKE DATA LINK CONN- ECTOR FUEL PUMP RELAY AUXILIARY COOLING FAN A/C COMPRESSOR CLUTCH AUXILIARY COOLING FAN COOLANT PRESSURE SWITCH BATTERY BLK WIRE BLK/ WHT WIRE BLK/WHT WIRE BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID BRAKE/ TRANSMISSION SHIFT INTERLOCK RELAY DAYTIME RUNNING LAMPS RELAY CRUISE CONTROL MODULE DAYTIME RUNNING LAMPS MODULE HEADLAMP DIMMER SWITCH FUEL CONTROL MODULE FUEL PUMP I/P CLUSTER LEFT HIGH/LOW BEAM HEADLAMP LEFT HORN LEFT PARK/ TURN SIGNAL LAMP PARK BRAKE SWITCH POWERTRAIN CONTROL MODULE (PCM) PROVISIONS FOR LEFT SIDE MARKER LAMP PROVISIONS FOR RIGHT SIDE MARKER LAMP RIGHT HIGH/LOW BEAM HEADLAMP RIGHT HORN RIGHT PARK/ TURN SIGNAL LAMP STARTER MOTOR RELAY TAN WIRE WATER IN-FUEL SENSOR (DIESEL) ENGINE COOLANT LEVEL SENSOR

BLK WIRE DAYTIME RUNNING LAMPS CONTROL MODULE (ATTACHED TO I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (LEFT SIDE OF DASH, ON RELAY BRACKET) DIODE NETWORK (ON I/P HARNESS) DK BLU WIRE DK GRN/WHT WIRE DRL INDICATOR FUSE BLOCK BREAKOUT) FUSIBLE LINK (16 GA- GAUGES FUSE 8 GRN WIRE HEADLAMP DIMMER SWITCH HEADLAMPS SWITCH OFF HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK IGNITION SWITCH INSTRUMENT CLUSTER LEFT HEAD- LAMP LO HI LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE LT LT ORG/ WIRE PARK BRAKE IN FOG LAMPS PARK BRAKE INDICATOR SWITCH (ON PARK BRAKE LEVER) PARK HEAD PNK IGNITION LAMP FEED HI BM INPUT HI BM INDICATOR RELAY CONTROL GROUND WIRE PNK WIRE RED WIRE RIGHT HEAD- LAMP RUN WIRE TAN WIRE WHT WIRE YEL WIRE

BLK WIRE FUSIBLE LINK (16 GA- GRN WIRE HEAD HEADLAMPS SWITCH HI BEAM INDICATOR HOT AT ALL TIMES INSTRUMENT CLUSTER LEFT HEADLAMP HI LO HEADLAMPS DIMMER SWITCH LT GRN WIRE OFF PARK RED WIRE RIGHT HEADLAMP HI LO TAN WIRE YEL WIRE

BLK WIRE DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) DK BLU/WHT WIRE DRL FUSE FUSE BLOCK GAUGES FUSE GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START IGNITION LAMP FEED HI BEAM FEED HI BEAM INDICATOR OUTPUT TO RELAY GROUND INSTRUMENT CLUSTER LEFT HIGH BEAM HEADLAMP LEFT LOW BEAM HEADLAMP LT GRN WIRE LT GRN/BLK WIRE LT LT OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (ON PARK BRAKE SUPPORT BRACKET) PNK/BLK WIRE PPL PPL BULB CHECK RIGHT HIGH BEAM HEADLAMP RIGHT LOW BEAM HEADLAMP TAN WIRE WHT WIRE YEL WIRE

1995 VFTC BLK WIRE GRN WIRE HEADLAMP DIMMER SWITCH HI BEAM INDICATOR HI LO HOT AT ALL TIMES LEFT HIGH BEAM HEADLAMP ASSEMBLY LEFT LOW BEAM HEADLAMP ASSEMBLY LIGHT SWITCH LT GRN WIRE LT INSTRUMENT CLUSTER OFF OFF HEAD HEAD PARK PARK RIGHT HIGH BEAM HEADLAMP ASSEMBLY RIGHT LOW BEAM HEADLAMP ASSEMBLY TAN 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

4.3L 5.7L 5.7L ONLY 4.3L ONLY 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 CRUISE CONTROL SYSTEM CRUISE SIGNAL 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 CRNK FUSE ECM BAT FUSE EGR CONTROL EGR ELECTONIC VACUUM REGULATOR SOLENIOD VALVE (TOP RIGHT FRONT OF ENGINE) 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 IDLE AIR CONTROL ACTUATOR (TOP REAR OF ENGINE) INJ FUSE KNOCK SENSOR INPUT ECT SIGNAL 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 ORG/ WIRE OXYGEN SENSOR GROUND PNK 26 27 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PPL 24 25 PPL/WHT WIRE RANGE SIGNAL A INPUT SPEED SIGNAL HIGH INPUT SPEED SIGNAL LOW RANGE SIGNAL B RANGE SIGNAL C MIL CONTROL RED WIRE RED/BLK WIRE TAN WIRE TAN/BLK 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 (NO LOCATION) 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

4.3L 5.7L 5.7L ONLY 4.3L ONLY 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 CRUISE CONTROL SYSTEM CRUISE SIGNAL 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 CRNK FUSE ECM BAT FUSE EGR CONTROL EGR ELECTONIC VACUUM REGULATOR SOLENIOD VALVE (TOP RIGHT FRONT OF ENGINE) 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 IDLE AIR CONTROL ACTUATOR (TOP REAR OF ENGINE) INJ FUSE KNOCK SENSOR INPUT ECT SIGNAL 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 ORG/ WIRE OXYGEN SENSOR GROUND PNK 26 27 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PPL 24 25 PPL/WHT WIRE RANGE SIGNAL A INPUT SPEED SIGNAL HIGH INPUT SPEED SIGNAL LOW RANGE SIGNAL B RANGE SIGNAL C MIL CONTROL RED WIRE RED/BLK WIRE TAN WIRE TAN/BLK 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 (NO LOCATION) 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