GMC Forward Control P3500 (1985-1999) hot in run or start Wiring diagrams

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, TURBO CHARGER POWER VALVE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS SENS HI IN A/T ISS SENS LO IN 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 BRAKE SWITCH IN BRN WIRE BRN/WHT WIRE BUSS BAR CLASS II DATA DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) DK BLU WIRE DK BLU/WHT 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, FUEL PUMP SWITCH/ENGINE OIL PRESSURE INDICATOR SENSOR GAUGES FUSE 8 GRY WIRE HAZARD LAMPS FLASHER (ABOVE STEERING COLUMN) 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 PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK INSTRUMENT CLUSTER WIRE PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL/WHT WIRE PRESS CTRL SOLENOID RED WIRE RED/BLK WIRE SENSOR GROUND SERVICE ENGINE SOON INDICATOR STOP-HAZ FUSE 11 STOPLAMP SWITCH IN TFT SENSOR IN TORQUE CONVERTER CLUTCH BRAKE, STOPLAMP SWITCH TRANS FLUID TEMP SENSOR TRANS RANGE "A" TRANS RANGE "B" TRANS RANGE "C" TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSMISSION FUSE 17 TWISTED WIRE PAIR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR CALIBRATOR (ABOVE ACCELERATOR PEDAL) VEHICLE SPEED SENSOR CALIBRATOR, ENGINE SHUTOFF SOLENOID VSS HI IN VSS LO IN VSS OUT YEL WIRE YEL/BLK WIRE

1995 VFTC BAT VOLT SENSE INPUT BATTERY BATTERY JUNCTION BLOCK BLK WIRE BLK/RED WIRE FUSE BLOCK FUSIBLE LINK (10 GA-RUST) GAGES FUSE GENERATOR HOT IN RUN OR START INSTRUMENT CLUSTER PNK/BLK WIRE RECTIFIER BRIDGE RED WIRE REGULATOR (SOLID STATE) STARTER CIRCUIT STATOR SW BAT FIELD (ROTOR) TURN ON INPUT VOLT- METER

BLK WIRE BRK SW INPUT BRN WIRE CRUISE CONTROL BRAKE SWITCH (ON BRAKE PEDAL SUPPORT) CRUISE CONTROL MODULE (BEHIND LEFT SIDE OF SHIPPING PANEL) CRUISE CONTROL SWITCH DK BLU WIRE DK GRN WIRE FUSE BLOCK GAGES FUSE GROUND GRY WIRE GRY/BLK WIRE HOT IN RUN OR START IGN NCA WIRE ON OFF ON/OFF INPUT PNK/BLK WIRE R/A R/A INPUT S/C S/C INPUT VEHICLE SPEED SENSOR BUFFER (LEFT SIDE OF SHIPPING PANEL) VSS INPUT

ALT FUSE BLK WIRE BRK SW INPUT BRN WIRE CRUISE CONTROL ACTIVATOR CRUISE CONTROL BRAKE SWITCH (ON BRAKE PEDAL SUPPORT) CRUISE CONTROL MODULE (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN WIRE FUSE BLOCK GROUND GRY WIRE HOT IN RUN OR START IGN ON OFF ON/OFF INPUT PNK/BLK WIRE R/A R/A INPUT S/C S/C INPUT TAN WIRE VEHICLE SPEED SENSOR BUFFER (LEFT SIDE OF SHIPPING PANEL) VSS INPUT

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 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

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

12 13 PNK WIRE 1222 1224 1225 1226 1350 PNK WIRE 2-3 SHIFT SOL CTRL FUEL INJ CTRL 4 WHEEL DRIVE LOW SWITCH 999 998 961 452 PPL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCELERATOR BRACKET) APP 1 SENSOR APP 2 SENSOR APP 3 SENSOR B/H BATTERY FEED 4 WHL LOW SW BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE CRUISE CONTROL SYSTEM CRUISE ON/OFF SIG DATA LINK CONNECTOR (NO LOCATION AVAILABLE) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/BLK WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENG SHUT-OFF CTRL ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) ENGINE GROUND (NO LOCATION AVAILABLE) ENGINE SHUT- OFF SOLENOID (TOP FRONT OF ENGINE) FUEL INJ CTRL FUEL SOLENOID (TOP FRONT OF ENGINE) FUEL SOLENOID DRIVER (TOP FRONT FUSE BLOCK FUSIBLE LINK (NO LOCATION AVAILABLE) GRY WIRE GRY/BLK WIRE GRY/RED WIRE HI RESOLUTION SIG HOT AT ALL TIMES HOT IN RUN OR START LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE OF ENGINE) OPTICAL SENSOR AND FUEL TEMPER- ATURE SENSOR (TOP FRONT OF ENGINE) ORG/ WIRE ORG/BLK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL 15 16 PRESSURE CONTROL SOL RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RESUME/ACCEL SIG SET/COAST SIG SYSTEM GND CLOSURE GRD APP 2 SENS GND APP 1 SENS GND APP 3 SENS GND SENSOR GND TAN WIRE TCC BRAKE SW TCC SOL 2-3 SHIFT SOL 1-2 SHIFT SOL TRANS FLUID TEMP (TFT) SENSOR TRANS FUSE TRANS INPUT SPD LO CKP SIG OPTICAL SENS GND OPTICAL SENS CAM SIG TRANS OUTPUT TRANSMISSION INPUT SPEED SENSOR VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (NO LOCATION AVAILABLE) VSS VSS INPUT VSS OUTPUT WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

ACCY ALT FUSE BLK WIRE BULB TEST COLD ADVANCE FAST IDLE TEMPERATURE SWITCH (RIGHT REAR OF ENGINE) COLD ADVANCE SOLENOID (TOP FRONT OF ENGINE) DK BLU WIRE FAST IDLE SOLENOID (TOP LEFT SIDE OF ENGINE) FUEL HEATER (TOP REAR OF ENGINE) FUEL SHUT- OFF SOLENOID (TOP FRONT OF ENGINE) FUSE BLOCK FUSIBLE LINK (12 GA- RUST) (NO LOCATION AVAILABLE) FUSIBLE LINK (20 GA- RUST) (ON STARTER MOTOR) FUSIBLE LINKS GLOW PLUG CONTROLLER (LEFT SIDE OF ENGINE) GLOW PLUG WAIT LAMP GROUND (NO LOCATION AVAILABLE) HOT AT ALL TIMES HOT IN RUN OR START HOT IN START INSTRUMENT CLUSTER LEFT BANK GLOW PLUGS LOCK OFF LT GRN/BLK WIRE NCA WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE RED WIRE RIGHT BANK GLOW PLUGS RUN WIRE WATER IN FUEL INDICATOR WATER-IN FUEL SENSOR (TOP REAR OF ENGINE) YEL/BLK WIRE