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

5 VOLT REF ACCELERATOR PEDAL POSITION MODULE (ATTACHED TO ACCELERATOR PEDAL) APP 1 SENSOR APP 2 SENSOR APP 3 SENSOR BLK WIRE BRN WIRE BRN/WHT WIRE CLOSURE GRD CLOSURE SIGNAL DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE 12 ENGINE SHUTOFF SOLENOID FUEL SOL CTRL FUEL SOL HIGH FUEL SOL LOW FUEL SOLE- NOID FUEL SOLENOID DRIVER (TOP LEFT OF ENGINE) GRN WIRE GRY WIRE HAZARD FLASHER (INNER LEFT SIDE OF MAIN SUPPORT BRACKET) HIGH LOW HIGH RES SIG HOT AT ALL TIMES HOT IN HOT IN RUN AND START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IGNITION TIMING STEPPER MOTOR (PART OF FUEL INJECTION PUMP) LOW HIGH LT BLU WIRE LT GRN WIRE OPTICAL FUEL TEMPERATURE SENSOR (PART OF FUEL INJECTION PUMP) ORG/ WIRE ORG/BLK WIRE PNK PNK PPL 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 WIRE PNK WIRE PNK/BLK WIRE PPL PPL PPL PPL PPL 28 29 30 31 32 PUMP CAM SIG RED WIRE RED/BLK WIRE RUN WIRE SENSOR GROUND STOP-HAZ FUSE 11 TAN WIRE TAN/BLK WIRE TCC/ STOPLAMP SWITCH (AT REAR OF BRAKE PEDAL SUPPORT BRACKET) TRANS FUSE 17 WHT WIRE YEL WIRE YEL/BLK WIRE

18 19 PNK WIRE A/C COMPRESSOR CLUTCH RELAY (RIGHT SIDE OF DRIVER'S ISLAND) A/C HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF THE A/C COMPRESSOR) BLK WIRE BLU WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM B FUSE 6 ENG BAT FUSE 10 FUEL LIFT PUMP (INSIDE RIGHT FRAME RAIL, AHEAD OF FUEL TANK) FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (IN UNDERHOOD FUSE/RELAY CENTER) FUEL PUMP SWITCH AND ENGINE OIL PRESSURE GAUGE SWITCH (LEFT REAR OF ENGINE) GAUGES FUSE 8 GRN WIRE GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK INDICATOR INSTRUMENT CLUSTER LT GRN WIRE MALFUNCTION INDICATOR LAMP (MIL) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK PNK WIRE PNK WIRE RED WIRE SERVICE THROTTLE SOON INDICATOR SPEED METER TAN WIRE WAIT TO WATER IN FUEL INDICATOR WATER IN-FUEL INPUT WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

"SERV THROTTLE SOON" IND 18 19 PNK WIRE A/C ENABLE GROUND GROUND 451 551 ANTILOCK BRAKES SYSTEM BATTERY BATTERY WASTEGATE SOL CTRL ESO SOLENOID CTLR BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN/WHT WIRE ENG 1 FUSE 15 ESO CTRL FUEL HEATER (TOP REAR OF ENGINE) FUEL INJECT CTRL FUSIBLE LINK FUSIBLE LINKS GLOW PLUG 1 GLOW PLUG 2 GLOW PLUG 3 GLOW PLUG 5 GLOW PLUG 7 GLOW PLUG 6 GLOW PLUG 4 GLOW PLUG 8 GLOW PLUG OUT GLOW PLUG RELAY (TOP REAR OF INTAKE MANIFOLD) GROUND GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK LT GRN WIRE NCA WIRE ORG/ WIRE PNK IGNITION WIRE PNK PNK 439 439 IGNITION IGNITION BATTERY MIL IND CTRL WIRE PNK PNK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND) PPL RED WIRE RELAY CTRL WASTEGATE SOLENOID WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1227 433 TFT SIG BARO PRESS SENS SIG 451 451 TCM GROUND TCM GROUND SENSOR RETURN 5 VOLT REF 8 9 PNK WIRE BAROMETRIC PRESSURE (BARO) SENSOR (TOP OF INTAKE MANIFOLD, LEFT SIDE IN BACK) BATTERY FEED BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE ECM BAT FUSE ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR ON FIRST CROSSMEMBER) ENG-BAT FUSE ENGINE SPEED SENS IN SENSOR RETURN TP SENS SIG ENGINE SPEED SENSOR (IN FUEL INJECTION PUMP) FROM LEFT BULKHEAD GROMMET) GENERATOR JUMPER BREAKOUT) GLOWPLUG CONTROL SWITCH BREAKOUT) GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES I-3 FUSE LT BLU/WHT WIRE LT GRN WIRE ORG/ WIRE PNK WIRE PPL PPL BRAKE PEDAL SW IN TCC PWM SOL CTRL PPL STOPLMP SW IN PRESS CTRL SOL (LO) IGN FEED PNK WIRE PRESS CTRL SOL. HI RED WIRE RED/BLK WIRE REF 5 VOLT RTN SENSOR SENSOR RTN SENSOR SIG SERVICE TRANS OUT SERIAL DATA SIG SENSOR TAN WIRE THROTTLE POSITION SENSOR (TPS) (RIGHT SIDE OF FUEL INJECTION PUMP) VEHICLE SPEED SIG WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID 8 9 PNK WIRE AUTOMATIC TRANSMISSION (A/T) (REAR OF ENGINE) BATTERY JUNCTION BLOCK (LEFT SIDE OF ENGINE BULKHEAD, ABOVE RELAY BRACKET) BLK WIRE BLU WIRE BRN WIRE CLOSED IN PARK, NEUTRAL CRK (START) DK BLU WIRE DK GRN WIRE ECM 1 FUSE FUEL INJECTION PUMP FUEL SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUSIBLE LINK (16 GA- GAUGES FUSE GLOW PLUGS GRN WIRE GRY WIRE HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGNITION SWITCH INSTRUMENT CLUSTER LOCK ON (RUN) OFF LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE PNK PNK PNK WIRE PNK WIRE POWER DISTRIBUTION SYSTEM PPL PPL PPL PNK 3 4 5 6 7 8 WIRE PPL STUD PRESSURE CONTROL SOLENOID RED WIRE RED/BLK WIRE SPEEDO- METER STARTER RELAY (ENGINE BULKHEAD RELAY BRACKET UNDER BATTERY JUNCTION BLOCK) STARTER SOLENOID (STARTER AT LOWER RIGHT SIDE OF ENGINE) STUD TCC PWM SOLENOID TRANS.) TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR TRANSMISSION RANGE (TR) PRESSURE SWITCH ASSEMBLY WATER IN FUEL WHT WIRE YEL WIRE YEL/BLK WIRE

B+ BREAKOUT) BATTERY JUNCTION BLOCK (LEFT SIDE OF ENGINE BULKHEAD, ABOVE RELAY BRACKET) BLK WIRE BLU WIRE BRN WIRE BULKHEAD GROMMET) DK BLU WIRE DK GRN WIRE ENG-1 FUSE 20 A FUEL HEATER (REAR OF INTAKE MANIFOLD, PART OF FUEL/WATER SEPARATOR) (FILTER) FUEL INJECTION PUMP COLD ADVANCE SOLENOID (IN FUEL INJECTION PUMP) FUSIBLE LINK FUSIBLE LINK (12 GA- FUSIBLE LINK (14 GA- FUSIBLE LINK (20 GA- FUSIBLE LINK FUSIBLE LINK FUSIBLE LINK FUSIBLE LINK FUSIBLE LINK GLOW PLUG STUD GLOWPLUG CONTROL SWITCH (REAR OF LEFT CYLINDER HEAD) GROUND GRY WIRE HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGN FEED LEFT BANK GLOWPLUGS (CYLINDER HEADS BELOW VALVE COVERS) LEFT GLOWPLUG BREAKOUTS) LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE PNK (COIL) WIRE PNK 12 13 15 WIRE PNK IGN FEED IND LAMP OUT GROUND WIRE PNK WIRE POWER DISTRIBUTION SYSTEM PPL (NOT USED) PPL PPL PNK 3 4 5 6 7 8 WIRE PPL STARTER FEED PPL/WHT WIRE PRESSURE DIFF SW BREAKOUT) RED WIRE RIGHT BANK GLOWPLUGS (CYLINDER HEADS BELOW VALVE COVERS) STUD TRANS FUSE VEHICLE SPEED SENSOR (VSS) (LEFT REAR OF TRANSMISSION, NEAR CENTER) VSS RTN GROUND IGN FEED VSS SIG VSS VSS OUT YEL/BLK WIRE

BATTERY JUNCTION BLOCK (LEFT SIDE OF ENGINE BULKHEAD, ABOVE RELAY BRACKET) BLK WIRE BLU WIRE DK BLU WIRE ECM-1 FUSE 20 A ENG-1 FUSE 20 A FUEL HEATER (REAR OF INTAKE MANIFOLD, PART OF FUEL/WATER SEPARATOR) (FILTER) FUEL INJECTION PUMP FUEL SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUSIBLE LINK FUSIBLE LINK (12 GA- FUSIBLE LINK (14 GA- FUSIBLE LINK (20 GA- FUSIBLE LINK FUSIBLE LINK GLOW PLUG STUD GLOWPLUG CONTROL SWITCH (REAR OF LEFT CYLINDER HEAD) GROUND GRY WIRE HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGN FEED LEFT BANK GLOWPLUGS (CYLINDER HEADS BELOW VALVE COVERS) LEFT GLOWPLUG BREAKOUTS) NCA WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE POWER DISTRIBUTION SYSTEM PPL PPL STARTER FEED RED WIRE RIGHT BANK GLOWPLUGS (CYLINDER HEADS BELOW VALVE COVERS) STUD

BATTERY JUNCTION BLOCK (LEFT SIDE OF ENGINE BULKHEAD, ABOVE RELAY BRACKET) BLK WIRE BULKHEAD GROMMET) CRK (START) DK BLU WIRE FROM GENERATOR B+ BREAKOUT) FUEL INJECTION PUMP COLD ADVANCE SOLENOID (IN FUEL INJECTION PUMP) FUSIBLE LINK (16 GA- GAUGES FUSE GLOW PLUGS HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGNITION SWITCH INSTRUMENT CLUSTER LOCK ON (RUN) OFF LT GRN/BLK WIRE NCA WIRE PNK IGN FEED IND LAMP OUT GROUND WIRE PNK WIRE POWER DISTRIBUTION SYSTEM PPL PPL STUD RED WIRE STARTER RELAY (ENGINE BULKHEAD RELAY BRACKET UNDER BATTERY JUNCTION BLOCK) STARTER SOLENOID (STARTER AT LOWER RIGHT SIDE OF ENGINE) STUD WATER IN FUEL WHT WIRE YEL WIRE YEL/BLK WIRE

2 3 PPL 2-3 SHIFT SOL CTRL ANTI-LOCK BRAKES SYSTEM BANK 2 SENSOR 1 (ON RIGHT EXHAUST PIPE BEFORE CATALYTIC CONVERTER) BLK LT BLU/ WIRE BLK WIRE BLK/WHT WIRE BLU/BLK WIRE BRN WIRE BRN/WHT WIRE CAMSHAFT POSITION SENSOR (INTERNAL TO DISTRIBUTOR) CMP LOW FUEL GAUGE PPL DK BLU WIRE DK BLU/WHT WIRE GRN/BLK WIRE HEATED OXYGEN IGN FEED KS SIGNAL LEFT KNOCK SENSOR (ON LOWER LEFT SIDE OF ENGINE) LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/ BLK WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE MAP SIGNAL IAT SIGNAL ECT SIGNAL NCA WIRE PNK 8 9 10 WIRE PNK IGN FEED SENS RTN SENS SIG WIRE PNK WIRE PNK/BLK WIRE PPL PPL CKP LOW VSS LOW VSS SIGNAL PPL PPL PPL/WHT WIRE RED/BLK WIRE RIGHT KNOCK SENSOR (ON LOWER RIGHT SIDE OF ENGINE) SENSOR RTN SENSOR SIGNAL T/P SIGNAL TAN WIRE TAN/WHT WIRE TFT SIGNAL MAF SIGNAL IAC HIGH IAC LOW INJECTOR 4 CTRL INJECTOR 3 CTRL VEHICLE CONTROL MODULE (VCM) (CENTER FRONT OF ENGINE COMPARTMENT) VSS WHT LT BLU/ WIRE WHT LT GRN/ WIRE WHT PPL/ WIRE YEL WIRE YEL/BLK WIRE

2 3 PPL AUTOMATIC TRANSMISSION BANK 1 SENSOR 1 (ON LEFT EXHAUST PIPE BEFORE CATALYTIC CONVERTER) BANK 1 SENSOR 2 (ON LEFT EXHAUST PIPE AFTER CATALYTIC CONVERTER) BANK 2 SENSOR 2 (ON RIGHT EXHAUST PIPE AFTER CATALYTIC CONVERTER) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/BLK WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE 12 ENG 1 FUSE 15 EXHAUST GAS RECIRCULATION VALVE SOLENOID (LEFT SIDE OF INTAKE PLENUM) FLUID TEMPERATURE SENSOR (INTERNAL) FORCE MOTOR FUEL INJ 1 FUEL INJ 2 FUEL INJ 3 FUEL INJ 5 FUEL INJ 4 FUEL INJ 6 FUEL INJ 7 FUEL INJ 8 GRN WIRE GRN/BLK WIRE GRY WIRE HEATED OXYGEN HOT IN RUN AND START I/P FUSE BLOCK IGNITION INTAKE AIR TEMP SENSOR (MOUNTED IN FRESH AIR INTAKE BEHIND AIR FILTER BOX) LT BLU/WHT WIRE LT GRN WIRE NCA WIRE PNK 8 9 10 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE PPL/ WHT WIRE PPL/WHT WIRE RED WIRE RED/BLK WIRE SOLENOID 1-2 SOLENOID 2-3 SWITCH PRESSURE TAN WIRE TAN/ WHT WIRE TAN/WHT WIRE TCC SOLENOID WHT LT BLU/ WIRE WHT PPL/ WIRE WHT TAN/ WIRE WHT WIRE YEL WIRE YEL/BLK WIRE