GMC Forward Control P3500 (1985-1999) i/p fuse block Wiring diagrams

4000 PULSES/MILE BLK WIRE BLU WIRE BRN WIRE CRUISE CONTROL MODULE (RADIATOR SUPPORT BRACKET) CRUISE CONTROL SWITCH CRUISE ON INPUT SET/COAST INPUT RESUME/ACCEL INPUT DK BLU WIRE DK GRN WIRE GRY WIRE GRY/BLK WIRE HAZARD LAMPS FLASHER HOT AT ALL TIMES HOT IN RUN I-3 FUSE I/P FUSE BLOCK LT BLU WIRE NCA WIRE OFF ORG/ WIRE PPL PPL DISENGAGE INPUT GROUND IGNITION BRAKE APPLIED INPUT R/A S/C STOP/HAZ FUSE STOPLAMP SWITCH (TOP OF BRAKE PEDAL) TORQUE CONVERTER CLUTCH AND STOPLAMPS SWITCH (TOP OF BRAKE PEDAL) VEHICLE SPEED INPUT VEHICLE SPEED SENSOR BUFFER (ABOVE ACCELERATOR PEDAL)

A/T BRN WIRE HOT IN I/P FUSE BLOCK LT GRN WIRE M/T PARK/NEUTRAL POSITION (PNP), BACKUP LAMP SWITCH (LEFT SIDE OF TRANS.) PROVISION FOR LEFT BACKUP LAMP PROVISION FOR RIGHT BACKUP LAMP RUN WIRE TURN SIGNAL FLASHER (I/P FUSE BLOCK) TURN-B/U FUSE

7.4L VIN N ALL EXCEPT 7.4L VIN N BRN WIRE DK GRN WIRE ENGINE GRN WIRE HOT IN I/P FUSE BLOCK LT GRN WIRE PARK/NEUTRAL POSITION (PNP), BACKUP LAMP SWITCH (LEFT SIDE OF TRANS.) PROVISION FOR BACKUP LAMPS (ON LEFT FRAME RAIL NEAR REAR LAMP HARNESS) PROVISION FOR NOT USED (NEAR BREAKOUT FOR STEERING COLUMN HARNESS) RUN WIRE TURN SIGNAL FLASHER (I/P FUSE BLOCK) TURN-B/U FUSE

BACKUP LAMPS CIRCUIT BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK GRN WIRE ENGINE CONTROLS SYSTEM (W/ DIESEL) GRN WIRE HAZARD HAZARD LAMPS FLASHER (ON INNER LEFT SIDE OF STEERING COLUMN SUPPORT BRACKET) HEAD OFF HEADLAMPS SWITCH HOT AT ALL TIMES HOT IN I/P FUSE BLOCK INSTRUMENT CLUSTER RIGHT TURN IND. INTERIOR LAMPS SYSTEM LEFT FRONT PARK/ TURN SIGNAL LAMP LEFT FRONT SIDE MARKER LAMP LEFT LICENSE LAMPS RIGHT LICENSE LAMPS LEFT REAR SIDE MARKER LAMP LEFT TURN IND LT BLU WIRE NCA WIRE NORMAL ORG/ WIRE PARK PPL PROVISION FOR CENTER HIGH MOUNTED STOP LAMP PROVISIONS FOR MARKER LAMPS (NEAR I/P FUSE BLOCK) RIGHT FRONT PARK/ TURN SIGNAL LAMP RIGHT REAR SIDE MARKER LAMP RIGHT TAIL/STOP, TURN SIGNAL LAMPS RUN WIRE STOP STOP-HAZ FUSE 11 TAIL TAIL LAMPS FUSE 7 TAIL STOP TAIL/STOP, TURN SIGNAL LAMPS TORQUE CONVERTER CLUTCH, STOP LAMPS SWITCH (AT BASE OF BRAKE PEDAL SUPPORT) TURN TURN B/U FUSE 5 TURN LEFT TURN RIGHT TURN SIGNAL FLASHER TURN SIGNAL SWITCH WHT WIRE YEL WIRE

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

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

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT FOR CRUISE CONTROL MODULE, TOWARD RELAYS) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE SENSOR (ON TOP FRONT OF ENGINE) FUEL GAUGE FUEL PUMP AND FUEL TANK SENDER (ON TOP OF FUEL TANK) FUEL PUMP/ OIL PRESSURE SWITCH (ON TOP LEFT REAR OF ENGINE) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP (MIL) "SERVICE ENGINE SOON" MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP CENTER FRONT OF ENGINE) MASS AIR FLOW SENSOR (RIGHT FRONT OF ENGINE COMP, ON AIR INTAKE ASSEMBLY) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK 22 23 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE RED WIRE RED/BLK WIRE SPEED METER TACH TAN WIRE THROTTLE POSITION SENSOR (ON THROTTLE BODY, TOP OF ENGINE) TRANS FUSE 17 WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 PNK PNK WIRE A/C COMP CYL SW A/C REQUEST SIGNAL AIR CONDITIONING SYSTEM ANTI-LOCK BRAKES SYSTEM PPL AUX ELECT COOLING FAN BRAKE SIGNAL SERIAL DATA PPL PPL 420 1807 B(+) BATTERY FEED RANGE SIGNAL B RANGE SIGNAL A 1225 1224 PNK WIRE BLK RED/ WIRE BLK WIRE BLK/WHT WIRE BLU/ WHT WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE COOLING FANS SYSTEM CRUISE CONTROL MODULE (ON RADIATOR SUPPORT BRACKET) CRUISE CTRL ENGAGED CRUISE ENGAGED SIG CYLINDER 1 CYLINDER 4 CYLINDER 5 CYLINDER 3 CYLINDER 6 CYLINDER 7 CYLINDER 2 CYLINDER 8 DISTRIBUTOR DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM B FUSE 6 EGR VALVE FEED EGR VLV CTRL ELEC SPK TIMING CTRL SIGNAL EST CTRL FUEL PMP RLY CTRL 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (LEFT SIDE OF ENGINE COMPT) GRN WIRE GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK IGN FEED IGNITION COIL (ON BRACKET AT REAR OF INTAKE PLENUM) IGNITION COIL MODULE (ON BRACKET AT REAR OF INTAKE PLENUM) LT BLU/BLK WIRE LT BLU/WHT WIRE ORG/ WIRE PCS HIGH INPUT SPEED SENS LOW INPUT SPEED SENS HIGH IC CNTRL PCS LOW GROUND GROUND SENS GROUND PNK 22 23 WIRE PNK IGN FEED WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (DLC) (BELOW DASH, NEAR STEERING COLUMN) 4 5 PPL FUEL LEVEL MODULE A/C REC PPL TCC/STOPLAMP INPUT RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SPARK PLUGS SPEED SENSOR INPUT VEHICLE CONTROL MODULE (VCM) (ON CENTER FRONT OF ENGINE COMPARTMENT) VSS OUTPUT SIGNAL VSS OUTPUT SIGNAL CHECK ENGINE LP CTRL 389 419 WHT DK GRN/ WIRE WHT WIRE WHT/BLK WIRE