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

1-2 SHIFT SOL 1227 433 TRANS FLUID TEMP SIG BARO SENSOR INPUT 2-3 SHIFT SOL CTRL 1-2 SHIFT SOL CTRL DIAGNOSTIC TEST 9 6 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) A/T INPUT SPEED SENSOR (LEFT FRONT SIDE OF TRANSMISSION) AUTOMATIC TRANSMISSION BAROMETRIC PRESSURE SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BRN WIRE DASH FUSE BLOCK DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE ECM BAT FUSE ENGINE SPEED SENSOR (IN FUEL INJECTION PUMP) ENGINE SPEED SIGNAL SENSOR GROUND TP SENSOR INPUT GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN HOT IN RUN OR START I-3 FUSE INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OUT PCS HI PCS LO IGNITION PNK WIRE PNK RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C WIRE PNK WIRE PPL PPL BRAKE SIGNAL TCC PWM CONTROL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RUN WIRE SERVICE TRANS OUTPUT SERIAL DATA SERVICE TRANSMISSION INDICATOR STOP LAMPS, TORQUE CONVERTER BRAKE SWITCH SYSTEM GROUND SYSTEM GROUND 452 416 SENSOR GROUND 5 VOLTS REF TAN WIRE TCC PWM SOL 2-3 SHIFT SOL THROTTLE POSITION SENSOR (RIGHT SIDE OF FUEL INJECTION PUMP) TRANS FUSE TRANSMISSION CONTROL MODULE (LEFT INTERIOR FIREWALL) TRANSMISSION TEMPERATURE SENSOR VEHICLE SPD OUTPUT VEHICLE SPEED INPUT INPUT SPEED SENS LO INPUT SPEED SENS HI VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER VEHICLE SPEED SENSOR BUFFER, FUEL INJECTION PUMP FUEL SHUT OFF SOLENOID PNK WIRE VSS INPUTS WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

BLK WIRE CONTROL AREA DELAY/ SPEED/ WASH CONTROL FUSE BLOCK FUSIBLE LINK GRY WIRE HOT IN ACCY OR RUN I/P GROUND (IN I/P HARNESS) IGN LT BLU WIRE MIST OFF ORG/ WIRE PARK SWITCH PNK WIRE PPL PULSE WASH PULSE SWITCH WHT WIRE WINDSHIELD WASHER PUMP WINDSHIELD WIPER MOTOR MODULE WINDSHIELD WIPER/ WASHER SWITCH WIPER FUSE

BLK WIRE CONTROL AREA DELAY/ SPEED/ WASH CONTROL FUSE BLOCK FUSIBLE LINK GRY WIRE HOT IN ACCY OR RUN IGN MIST OFF PARK SWITCH PNK WIRE PPL PULSE WASH PULSE SWITCH WHT WIRE WINDSHIELD WASHER PUMP (LEFT KICK PANEL) (CENTER OF I/P) WINDSHIELD WIPER MOTOR MODULE WINDSHIELD WIPER/ WASHER SWITCH WIPER FUSE

ACCY ACCY BULB TEST LOCK AUDIO ALARM MODULE AUTO APPLY PARK BRAKE AUX AUX CIRCUIT BREAKER AUXILIARY COOLING FAN RELAY BATTERY BATTERY JUNCTION BLOCK BLK WIRE BLK/RED WIRE BRAKE PRESSURE WARNING SWITCH BRN WIRE BRN/WHT WIRE BULB TEST DAYTIME RUNNING LAMPS AUXILIARY COOLING FAN RELAY DAYTIME RUNNING LAMPS MODULE DAYTIME RUNNING LAMPS RELAY DK GRN WIRE DOME LAMP ECM-BAT FUSE ACC-RADIO FUSE FROM PANEL DIMMER SWITCH ASSEMBLY (INTERIOR LIGHTS SYSTEM) FUEL PUMP OIL PRESSURE SWITCH FUEL PUMP RELAY POWERTRAIN CONTROL MODULE FUSE BLOCK FUSIBLE FUSIBLE LINK GAGES FUSE GENERATOR GRY WIRE HAZARD FLASHER HEADLIGHT SWITCH ASSEMBLY HORN RELAY HTR FUSE I/P CLUSTER IGNITION SWITCH INSTR-LPS LPS BUS FUSE LINK LOCK LOCK OFF OFF ORG/ WIRE PARK BRAKE WARNING SWITCH PCM PNK WIRE PNK/ WHT WIRE PPL PWR CIRCUIT BREAKER RED WIRE RELAY RUN WIRE SHUNT STARTER MOTOR STOP- HZ FUSE STOPLAMP SWITCH TAIL LPS FUSE HORN/DM FUSE TAN/WHT WIRE TO ALT, ECM-CRANK, TURN-B/U, TRANS, INJECTOR FUSES AND IGNITION COIL TRANSMISSION INSTRUMENT AUDIO POSITION CLUSTER ALARM INDICATOR MODULE LAMP WHT PNK/ WIRE WHT WIRE WIPER FUSE WIPER SWITCH

ALT FUSE AUDIO ALARM MODULE BACKUP LAMP SWITCH CRUISE CONTROL BRAKE SWITCH CRUISE CONTROL MODULE CRUISE CONTROL SWITCH DK BLU WIRE ECM CRANK FUSE EVAPORATIVE EMISSIONS CANISTER PURGE SOLENOID FUSE BLOCK GENERATOR IDLE SPEED CONTROL ACTUATOR IGNITION COIL IGNITION SWITCH INJ FUSE INJECTOR 1 INJECTOR 2 INSTRUMENT CLUSTER PRINTED CIRCUIT LINEAR EGR SOLENOID VALVE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) RED WIRE TCC/ STOPLAMP SWITCH TRANS FUSE TRANSMISSION TURN SIGNAL FLASHER TURN-B/U FUSE VEHICLE SPEED SENSOR BUFFER WHT WIRE

BLK WIRE FUSE BLOCK GRY WIRE HI LO HOT IN ACCY OR RUN LT BLU WIRE MIST OFF PNK WIRE PPL PROVISIONS FOR WIPER/WASHER MODULE PULSE PULSE WIPER/ WASHER SWITCH WASH PULSE WHT WIRE WIPER FUSE WIPER MOTOR CONNECTOR

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

3 121 PNK WIRE 4.3L AND 7.4L 5.7L ACCY ALT FUSE BLK WIRE BLK/RED WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE BULB TEST DISTRIBUTOR (CENTER REAR OF ENGINE) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENGINE COOLANT TEMPERATURE SENSOR (TOP FRONT OF ENGINE) FUSE BLOCK GRY WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START IDLE SPEED ACTUATOR CONTROL SOLENOID (NO LOCATION AVAILABLE) IGNITION COIL (TOP RIGHT REAR OF ENGINE) IGNITION SWITCH INSTRUMENT CLUSTER KNOCK SENSOR (LEFT REAR OF ENGINE, NEAR OIL PRESSURE SENDER) KNOCK SENSOR MODULE (TOP RIGHT SIDE OF ENGINE) LOCK OFF LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION (SERVICE ENGINE SOON) INDICATOR MANIFOLD ABSOLUTE PRESSURE SENSOR (ABOVE VALVE COVER) NCA WIRE ORG/ WIRE PNK 26 27 WIRE PNK WIRE PNK/BLK WIRE PPL PPL 2 3 4 PPL 24 25 PPL/WHT WIRE PROVISIONS FOR TACHOMETER RED WIRE RED/BLK WIRE RUN WIRE TAN/BLK WIRE TCC/BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) THROTTLE POSITION SENSOR (ON THROTTLE BODY) TRANS FUSE WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

BLK WIRE BLK/RED WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DIAGNOSIS TEST TP SIGNAL INJECTOR 1 CTRL DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM BAT FUSE ECM-CRNK FUSE ECT SIGNAL EGR CONTROL ENGINE COOLANT TEMPERATURE SENSOR (TOP FRONT OF ENGINE) ENGINE GROUND FUEL PUMP RELAY CTRL FUEL PUMP SIGNAL MAP SIGNAL FUSE BLOCK GRY WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START IC BYPASS TP/ECT GROUND MAP GROUND IC SIGNAL VSS SIGNAL VSS TP REFERENCE IDLE AIR CONTROL ACTUATOR (TOP REAR OF ENGINE) INJ FUSE KNOCK SENSOR SIGNAL LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (TOP REAR OF ENGINE) MAP REFERENCE IGNITION FUSED BATTERY FEED ORG/ WIRE ORG/BLK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PPL 3 4 PPL/WHT WIRE RED WIRE SERIAL DATA 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) THROTTLE POSITION SENSOR (TOP RIGHT SIDE OF ENGINE) WHT WIRE WHT/BLK WIRE YEL WIRE

ACCY ALT FUSE BLK WIRE BLK/RED WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE BULB TEST DISTRIBUTOR (TOP REAR OF ENGINE) DK BLU WIRE DK GRN/WHT WIRE EGR SOLENOID (TOP RIGHT SIDE OF ENGINE) ENGINE GROUND FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST MANIFOLD) HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START IGNITION COIL (TOP OF ENGINE NEAR DISTRIBUTOR) IGNITION SWITCH INSTRUMENT CLUSTER KNOCK SENSOR (RIGHT SIDE OF ENGINE) LOCK OFF LT BLU WIRE LT GRN/YEL WIRE MALFUNCTION (SERVICE ENGINE SOON) INDICATOR NCA WIRE ORG/ WIRE PNK PPL WIRE PNK WIRE PNK/BLK WIRE PPL 3 4 PPL/WHT WIRE PROVISIONS FOR TACHOMETER RED WIRE RUN WIRE TAN/BLK WIRE VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT WIRE