GMC Forward Control P3500 (1985-1999) dk blu Wiring diagrams

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/T ISS HI IN A/T ISS LO IN AUTO TRANSMISSION INPUT SHAFT SPEED SENSOR (INSIDE FRONT OF TRANSMISSION) AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE DK BLU/WHT WIRE ECM BATT FUSE ECM I FUSE ECT SENS INPUT ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP FRONT OF ENGINE) FUSE GAUGES FUSE GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN TCC PWM SOL TCC PWM SOLENOID TCC/STOP- LAMP SWITCH (ON BRAKE PEDAL BRACKET) THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN VEHICLE CONTROL MODULE (VCM) (BEHIND LEFT HEADLIGHT) 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/T ISS HI IN A/T ISS LO IN AUTO TRANSMISSION INPUT SHAFT SPEED SENSOR (INSIDE FRONT OF TRANSMISSION) AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE DK BLU/WHT WIRE ECM BATT FUSE ECM I FUSE ECT SENS INPUT ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP FRONT OF ENGINE) FUSE GAUGES FUSE GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN TCC PWM SOL TCC PWM SOLENOID TCC/STOP- LAMP SWITCH (ON BRAKE PEDAL BRACKET) THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN VEHICLE CONTROL MODULE (VCM) (BEHIND LEFT HEADLIGHT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

A/C COMPRESSOR CLUTCH RELAY (ENGINE FIREWALL RELAY BRACKET) A/C COMPRESSOR HIGH PRESSURE CUTOFF SWITCH (REAR OF A/C COMPRESSOR) A/C COMPRESSOR REFRIGERANT PRESSURE SWITCH (ON A/C ACCUMULATOR) BLK WIRE DIODE A/C COMPRESSOR CLUTCH DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG-BAT FUSE GRN WIRE GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK ORG/ WIRE VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) W/ VCM W/O VCM WHT (OR WIRE WHT WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/T ISS HI IN A/T ISS LO IN AUTO TRANSMISSION INPUT SHAFT SPEED SENSOR (INSIDE FRONT OF TRANSMISSION) AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE DK BLU/WHT WIRE ECM BATT FUSE ECM I FUSE ECT SENS INPUT ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP FRONT OF ENGINE) FUSE GAUGES FUSE GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN TCC PWM SOL TCC PWM SOLENOID TCC/STOP- LAMP SWITCH (ON BRAKE PEDAL BRACKET) THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN VEHICLE CONTROL MODULE (VCM) (BEHIND LEFT HEADLIGHT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

BLK WIRE BLU WIRE BREAKOUT FOR HEADLAMP SWITCH) BULB TEST DAYTIME RUNNING LAMPS MODULE (ATTACHED TO I/P HARNESS AT STEERING COLUMN) DAYTIME RUNNING LAMPS RELAY (ON MAIN SUPPORT BRACKET AT DRIVER'S ISLAND) DAYTIME RUNNING LAMPS RELAY 2 DIODE NETWORK DK BLU WIRE DK GRN/WHT WIRE DRL INDICATOR FOR LEFT HEADLAMP) FUSIBLE LINK (16 GA- GAUGES FUSE GRN WIRE HEAD- LAMP DIMMER SWITCH HEADLAMPS SWITCH HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK IGNITION SWITCH INSTRUMENT CLUSTER INSTRUMENT CLUSTER SYSTEM LEFT HEAD- LAMP LEFT HIGH BEAM HEAD- LAMP LO HI LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE PARK BRAKE IN FOG LAMPS PARK BRAKE INDICATOR SWITCH (ON PARK BRAKE) PARK HEAD OFF PNK IGNITION LAMP FEED HI BM FEED HI BM INDICATOR RELAY OUT GROUND WIRE PNK WIRE RED WIRE RIGHT HEAD- LAMP RIGHT HIGH BEAM HEAD- LAMP RUN WIRE TAN WIRE WHT WIRE YEL WIRE

BLK WIRE BLU WIRE BREAKOUT FOR HEADLAMP SW) BULB TEST DAYTIME RUNNING LAMPS MODULE (ATTACHED TO I/P HARNESS AT STEERING COLUMN) DAYTIME RUNNING LAMPS RELAY (ON MAIN SUPPORT BRACKET AT DRIVER'S ISLAND) DIODE NETWORK DK BLU WIRE DK GRN/WHT WIRE DRL INDICATOR FUSIBLE LINK (16 GA- GAUGES FUSE GRN WIRE HEAD- LAMP DIMMER SWITCH HEADLAMPS SWITCH HI BEAM INDICATOR HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK IGNITION SWITCH INSTRUMENT CLUSTER INSTRUMENT CLUSTER SYSTEM LEFT HEAD- LAMP LO HI HI LO 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) PARK HEAD OFF PNK IGNITION LAMP FEED HI BM FEED HI BM INDICATOR RELAY OUT GROUND WIRE PNK WIRE RED WIRE RIGHT HEAD- LAMP RUN WIRE TAN WIRE WHT WIRE YEL WIRE

4.3L A/T ACC BUS AUTOMATIC TRANSMISSION AUXILIARY ENGINE COOLANT FAN RELAY BRN WIRE CAMSHAFT POSITION SENSOR (5.7L) CLUTCH PEDAL POSITION SWITCH COLD ADVANCE SOLENOID AND ENGINE COOLANT TEMPERATURE SWITCH FUEL HEATER CRANK FUSE 18 CRK (START) LOCK ON (RUN) OFF CRK (START) ON (RUN) LOCK OFF CRK (START) ON (RUN) OFF DIESEL DK BLU WIRE ENG 1 FUSE 15 ENGINE SHUT-OFF SOLENOID FUEL SOLENOID DRIVER EVAP CANISTER VENT VALVE (4.3L) EVAPORATIVE EMISSIONS CANISTER PURGE VALVE FROM FUSIBLE LINK GAS GLOW PLUG CONTROLLER HEATED OXYGEN SENSOR BANK 1 SENSOR 1 CAMSHAFT POSITION SENSOR (4.3L) HEATED OXYGEN SENSOR BANK 2 SENSOR 1 HEATED OXYGEN SENSOR BANK 1 SENSOR 2 HEATED OXYGEN SENSOR BANK 2 SENSOR 2 IGNITION SWITCH IN-LINE FUSE BLOCK (NEAR RIGHT SIDE OF STEERING COLUMN) LOCK M/T MASS AIR FLOW SENSOR (4.3L/ 5.7L) ORG/ WIRE PARK/NEUTRAL POSITION AND BACKUP LAMPS SWITCH PNK PNK WIRE PNK WIRE PROVISIONS FOR WINDSHIELD WASHER MOTOR RADIO FUSE 4 RED WIRE TO I/P FUSE BLOCK (DIAGRAM 4 OF 4) TRANS FUSE 17 WATER IN FUEL INDICATOR SENSOR WHT WIRE WINDSHIELD WIPER/ WASHER SWITCH WIPER FUSE 14 YEL WIRE

1996 VFTC ACC BUS AUTOMATIC TRANSMISSION AUTOMATIC TRANSMISSION (A/T) BRN WIRE CLUTCH PEDAL POSITION (CPP) SWITCH CRK (START) LOCK ON (RUN) OFF CRK (START) ON (RUN) LOCK OFF CRK (START) ON (RUN) OFF DIESEL DK BLU WIRE ENG 1 FUSE EVAPORATIVE EMISSIONS (EVAP) CANISTER PURGE SOLENOID VALVE FROM FUSIBLE LINK FUEL HEATER FUSE OUTPUT- ACCESSORY TYPE 3 FUSE GAS GLOW PLUG CONTROL SWITCH HEATED OXYGEN SENSOR HEATED OXYGEN SENSOR CAMSHAFT POSITION (CMP) SENSOR I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGNITION SWITCH LEFT POST CONVERTER (5.7L VIN R LEFT PRE- CONVERTER LINEAR EXHAUST GAS RECIRC- ULATION (EGR) SOLENOID VALVE LOCK MANUAL TRANSMISSION MASS AIR FLOW (MAF SENSOR) NCA WIRE ORG/ WIRE PARK/NEUTRAL POSITION (PNP), BACKUP LAMPS SWITCH PNK PNK WIRE PNK WIRE POST CONVERTER (4.3L VIN W PROVISIONS FOR WIPER/ WASHER MOTOR RADIO FUSE RED WIRE RIGHT POST CONVERTER (5.7L VIN R RIGHT PRE- CONVERTER TO I/P FUSE BLOCK: (AUX, I-3, TURN B/U,, HTR FUSES) TRANS FUSE VEHICLE CONTROL MODULE (VCM) WATER- IN-FUEL SENSOR AUXILIARY ENGINE COOLANT FAN RELAY WHT WIRE WINDSHIELD WIPER/ WASHER SWITCH WIPER FUSE YEL WIRE

14 GA (BLK) WIRE 1996 VFTC 7.4L VIN J (L29) ENGINE, 7.4L VIN N (L19) ENGINE 7.4L VIN J, 6.5L VIN F ENGINES AUTOMATIC TRANSMISSION BRN WIRE CAMSHAFT POSITION SENSOR (7.4L VIN J DK BLU WIRE ECM-1 FUSE,, GAUGES FUSE ENG-1 FUSE TRANS FUSE ENGINE EVAPORATIVE EMISSIONS CANISTER PURGE SOLENOID (7.4L VIN J FAN CONTROL RELAY FROM FUSIBLE LINK FUEL HEATER (6.5L VIN F ENGINE) FUSE OUTPUT- ACCESSORY TYPE 3 FUSE GLOW PLUG CONTROL RELAY (6.5L VIN F ENGINE) HEATED OXYGEN SENSOR NO.1 HEATED OXYGEN SENSOR NO.2 HEATED OXYGEN SENSOR NO.3 HEATED OXYGEN SENSOR NO.4 I/P AUXILIARY FUSE BLOCK (MOUNTED ON I/P FUSE BLOCK) CRANK FUSE I/P FUSE BLOCK (MOUNTED ON THE I/P) IGNITION COIL (7.4L VIN N ENGINE) IGNITION SWITCH LOCK OFF MASS AIR FLOW SENSOR (7.4L VIN J ENGINE) NCA WIRE ORG/ WIRE PNK PNK WIRE PNK WIRE PPL PROVISIONS FOR WIPER/WASHER MOTOR RADIO FUSE RED WIRE RUN WIRE STARTER SOLENOID (7.4L VIN N ENGINE) VEHICLE CONTROL MODULE LINEAR EGR SOLENOID VALVE WATER IN-FUEL INDICATOR SENSOR (6.5L VIN F ENGINE) WHT WIRE WIPER FUSE YEL WIRE

A/T ACCY BATTERY BATTERY JUNCTION BLOCK BLK WIRE CLUTCH PEDAL POSITION SWITCH (TOP OF CLUTCH PEDAL SUPPORT) DIESEL ONLY DK BLU WIRE DK BLU/WHT WIRE ENGINE CONTROLS SYSTEM (COMMERCIAL DIESEL ONLY) FUSIBLE LINK FUSIBLE LINK (10 GA-RUST) IGNITION SWITCH IN LINE CRANK FUSE 18 (COMMERCIAL) OR I/P FUSE BLOCK, CRANK FUSE 18 (MOTOR HOME) LOCK M/T OFF PARK/NEUTRAL POSITION AND BACKUP LAMPS SWITCH (LEFT SIDE OF TRANSMISSION) PPL PPL M/T PULL- IN COIL HOLD- IN COIL RED WIRE RUN WIRE SECONDARY BATTERY (DIESEL) STARTER MOTOR STARTER SOLENOID WHT WIRE YEL WIRE