GMC Forward Control P3500 (1985-1999) org/ 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)

3 4 5 6 7 8 9 10 11 12 13 14 15 16 PNK PNK WIRE A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FROM TPS BREAKOUT) FUEL GAUGE FUEL PUMP SWITCH, ENGINE OIL PRESSURE GAUGE SENSOR (TOP LEFT REAR OF ENGINE) FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP REAR OF ENGINE) MAP REF LO MASS AIR FLOW SENSOR (MAF) (MOUNTED IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK PNK PNK 2 3 4 5 WIRE PNK PNK WIRE PNK WIRE PPL RED WIRE RED/BLK WIRE REF LO TEMP REF THROTTLE POSITION (TP) SENSOR (ON THROTTLE BODY, TOP OF ENGINE) SENSOR BREAKOUT) SPEEDO- METER TACHO- METER TAN WIRE WHT WIRE YEL WIRE

3 4 5 6 7 8 9 10 11 12 13 14 15 16 PNK PNK WIRE 389 419 VSS OUTPUT MIL CTRL 420 1807 PPL PPL BRAKE SIG SERIAL DATA 440 1225 1224 IGN FEED RANGE SIG "B" RANGE SIG "A" A/C REQUEST SIG A/C SYSTEM A/T INPUT SPEED SENSOR (TRANSMISSION, LEFT FRONT) ANTI-LOCK BRAKES SYSTEM BLK RED/ WIRE BLK WIRE BLK/WHT WIRE BLU/ WHT WIRE BRN WIRE BRN/WHT WIRE BULKHEAD GROMMET TOWARD IGNITION SW) CLUTCH PEDAL POSITION SWITCH (LEFT SIDE OF BRAKE PEDAL BRACKET) CLUTCH SIG CYLINDER NO.2 CYLINDER NO.1 CYLINDER NO.5 CYLINDER NO.3 CYLINDER NO.4 CYLINDER NO.6 DISTRIBUTOR (TOP REAR OF ENGINE) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM B FUSE 6 EGR VALVE CTRL FEED IGNITION FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) FUEL PUMP RELAY (ON FIRE- WALL, UNDER BATTERY JUNCTION BLOCK) GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGN FEED IGNITION COIL (TOP RIGHT SIDE OF ENGINE) IGNITION CONTROL MODULE (RIGHT TOP OF ENGINE) LT BLU/WHT WIRE ORG/ WIRE PCS SOL (HI) INPUT SPD SENS SIG INPUT SPD SENS RTN TIMING CTRL SIG PCS SOL (LO) SYSTEM GROUND SYSTEM GROUND GROUND 451 451 470 PNK IGN FEED WIRE PNK WIRE PPL PPL FUEL LEVEL PRESSURE SWITCH IN RANGE SIG "C" RED WIRE RED/BLK WIRE RETURN CONTROL TIMING SHIFT INTERLOCK SYSTEM PPL SIGNAL CONTROL TIMING SPARK PLUGS TCC/STOP LAMPS SWITCH (RIGHT SIDE OF STEERING COLUMN UPPER SUPPORT) VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPARTMENT) WHT WIRE WHT/BLK WIRE

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG-B FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FROM MAF SENSOR BREAKOUT) FROM TP SENSOR BREAKOUT) FUEL GAUGE FUEL PUMP SWITCH, ENGINE OIL PRESSURE GAUGE SENSOR (TOP LEFT REAR OF ENGINE) FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 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) INSTRUMENT CLUSTER INTAKE AIR TEMPERATURE (IAT) SENSOR (IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) LT BLU/WHT WIRE LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP RIGHT REAR OF ENGINE) MAP MASS AIR FLOW (MAF) SENSOR (IN FRESH AIR INTAKE BEHIND AIR FILTER BOX) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK 10 11 12 13 14 15 16 17 WIRE PNK 5 6 WIRE PNK PNK PNK PNK 1 2 3 4 WIRE PNK PNK WIRE PNK WIRE PPL PPL 1 2 PPL 8 9 RED WIRE RED/BLK WIRE REF LO REF LO TEMP REF THROTTLE POSITION (TP) SENSOR (THROTTLE BODY, TOP OF ENGINE) SERVICE ENGINE SOON INDICATOR SPEEDO- METER TACHO- METER TAN WIRE TRANS FUSE 17 WHT WIRE YEL WIRE

389 419 VSS OUTPUT MIL CTRL 440 1225 1224 IGN FEED RANGE SIG "B" RANGE SIG "A" A/C REQUEST SIG A/C SW IN A/C SYSTEM A/T INPUT SPEED SENSOR (TRANSMISSION, LEFT FRONT) BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION SWITCH (TOP OF CLUTCH PEDAL SUPPORT) CLUTCH SIG CYLINDER 1 CYLINDER 4 CYLINDER 5 CYLINDER 3 CYLINDER 6 CYLINDER 7 CYLINDER 2 CYLINDER 8 DISTRIBUTOR (TOP REAR OF ENGINE) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM B FUSE 6 EGR CTRL FROM LEFT BULKHEAD GROMMET) PPL FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) FUEL PUMP RELAY (ENGINE BULKHEAD RELAY BRACKET UNDER BATTERY JUNCTION BLOCK) GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGN FEED IGNITION COIL (TOP RIGHT SIDE OF ENGINE) IGNITION CONTROL MODULE (BRACKET AT TOP EDGE OF RIGHT CYLINDER HEAD) IGNITION FEED LT BLU/WHT WIRE ORG/ WIRE PCS SOL (HI) INPUT SPD SENS SIG INPUT SPD SENS RTN TIMING CTRL SIG PCS SOL (LO) SYSTEM GND SYSTEM GND GND 451 451 470 PNK IGN FEED WIRE PNK PNK WIRE PNK WIRE PPL PPL 1 2 PPL 2 4 5 16 DATA LINK CONNECTOR (DLC) (BELOW DASH, NEAR STEERING COLUMN) PPL ANTI-LOCK BRAKE SYSTEM PPL FUEL LEV PPL PPL 420 1807 BRAKE SIG SERIAL DATA RANGE SIG "C" RED WIRE RED/ BLK WIRE RED/BLK WIRE SHIFT INTERLOCK SYSTEM SPARK PLUGS TCC/ STOP LAMPS SWITCH (RIGHT SIDE OF STEERING COLUMN UPPER SUPPORT) TIMING CONTROL RETURN TIMING CONTROL SIGNAL) VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) WHT WIRE WHT/ DK BLU WIRE WHT/BLK WIRE

1-2 SHIFT 1226 1225 TR SWITCH C TR SWITCH B TR SWITCH A 2-3 SHIFT A/C REQUEST SIG ANTILOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION AUTOMATIC TRANSMISSION INPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) BATTERY BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE CLOSURE SIGNAL BOOST SENSOR SIG PRESS CTRL SOL VLV LO DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECT SIGNAL GRN WIRE GRY WIRE GRY/BLK WIRE LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/WHT WIRE LT PNK WIRE OR DK PNK WIRE ORG/ WIRE ORG/BLK WIRE OUTPUT SHAFT SPEED SENSOR PNK PNK PPL 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL PPL 28 29 30 31 32 PPL TCC/ABS BRAKE SW STOPLAMP SWITCH CRIUSE SET/COAST SIG 20 84 PPL/WHT WIRE PRESSURE CONTROL SOLENOID VALVE RANGE MODE SELECTOR TRANSMISSION TEMPERATURE SENSOR RED WIRE RED/BLK WIRE RESUME SENSOR GND SET- SOLENOID VALVE SOLID STATE SPEED CONTROL SWITCH TAN WIRE TAN/BLK WIRE TCC PWM SOLENOID VALVE TIMING STEPPER MTR (LOW) TIMING STEPPER MTR (LOW) TRANSMISSION SPEED INPUT WHT WIRE YEL WIRE YEL/BLK (OR RED/BLK) WIRE YEL/BLK 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

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