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

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

BLK WIRE GAUGES FUSE 8 GRY WIRE HORN/DM FUSE 3 HOT AT ALL TIMES HOT IN RUN AND START HOT W/ PARK OR HEADLAMPS SWITCH ON I/P FUSE BLOCK INSTR LPS FUSE 16 INSTRUMENT CLUSTER LAMP ON INPUT GROUND POWER (BATTERY) SEAT BELT INPUT ORG/ WIRE PNK POWER (IGNITION) WIRE PNK WIRE SEAT BELT LAMP OUTPUT SEAT BELTS ALARM MODULE (AT THE BOTTOM OF THE I/P FUSE BLOCK) YEL WIRE

1995 VFTC AUDIO ALARM MODULE BATTERY INPUT GROUND BLK WIRE FASTEN BELTS INDICATOR FASTEN BELTS OUT FUSE BLOCK GAGES FUSE GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START HOT WITH HEADLIGHT SWITCH IN PARK OR HEAD IGN ON INPUT INST LPS FUSE INSTRUMENT CLUSTER KEY-IN WARNING BUZZER SWITCH LEFT DOOR JAMB SWITCH LIGHTS ON INPUT SAFETY BELT INPUT LT GRN WIRE ORG/ WIRE PNK/BLK WIRE SAFETY BELT INPUT SAFETY BELT RETRACTOR SWITCH (IN DRIVER'S SAFETY BELT BUCKLE) STOP- HZ FUSE TAN WIRE YEL WIRE

AUDIO ALARM MODULE BLK WIRE FASTEN BELTS INDICATOR FUSE BLOCK GAUGES FUSE GRY WIRE HORN/DM FUSE HOT AT ALL TIMES HOT IN RUN OR START HOT WITH HEADLIGHT SWITCH IN PARK OR HEAD INSTR LPS FUSE INSTRUMENT CLUSTER ORG/ WIRE PNK/BLK WIRE YEL 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

1 2 PPL 1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD 4.3L 5.7L AND 7.4L B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ECM BAT FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (NO LOCATION AVAILABLE) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST MANIFOLD) HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK 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