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

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS HI IN A/T ISS LO IN A/T OUTPUT SPEED SENSOR ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE BUSS BAR GAUGES FUSE 8 DATA CLASS II DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE, CRUISE CONTROL MODULE ENGINE CONTROLS SYSTEM FUEL INJECTORS (ENGINE CONTROLS SYSTEM) FUEL PUMP RELAY, SWITCH GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (PARTIAL) (BELOW DASH NEAR STEERING COLUMN) PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN SERVICE ENGINE SOON INDICATOR TCC PWM SOL TCC PWM SOLENOID TCC/ STOP LAMPS SWITCH TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN TWISTED WIRE PAIR VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 3-2 SHIFT SOL 3-2 SHIFT SOLENOID A/C COMPRESSOR RELAY, GENERATOR PNK WIRE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS SENS HI IN A/T ISS SENS LO IN APP 1 SIGNAL IN APP 2 SIGNAL IN APP 3 SIGNAL IN AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH IN BRN WIRE BRN/WHT WIRE BUSS BAR CLASS II DATA DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENSOR IN ELECTRONIC BRAKE CONTROL MODULE ENGINE COOLANT TEMPERATURE SENSOR (TOP FRONT OF ENGINE) FUEL PUMP RELAY, ENGINE OIL PRESSURE INDICATOR SENSOR GAUGES FUSE 8 GRY WIRE HAZARD LAMPS FLASHER (ABOVE STEERING COLUMN) HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL/WHT WIRE PRESS CTRL SOLENOID RED WIRE RED/BLK WIRE SENSOR GROUND SERVICE ENGINE SOON INDICATOR STOP-HAZ FUSE 11 STOPLAMP SWITCH IN TFT SENSOR IN TORQUE CONVERTER CLUTCH, STOPLAMP SWITCH TRANS FLUID TEMP SENSOR TRANS RANGE "A" TRANS RANGE "B" TRANS RANGE "C" TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSMISSION FUSE 17 TWISTED WIRE PAIR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER VEHICLE SPEED SENSOR BUFFER (ABOVE ACCELERATOR PEDAL) VSS HI IN VSS LO IN VSS OUT YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/C COMPRESSOR RELAY, GENERATOR, SEAT BELT/ HEADLAMPS ALARM MODULE A/T INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T ISS HI IN A/T ISS LO IN A/T OUTPUT SPEED SENSOR ANTI-LOCK BRAKES, CRUISE CONTROL, SHIFT INTERLOCK SYSTEMS AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE BUSS BAR GAUGES FUSE 8 DATA CLASS II DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE, CRUISE CONTROL MODULE ENGINE CONTROLS SYSTEM FUEL INJECTORS (ENGINE CONTROLS SYSTEM) FUEL PUMP RELAY, SWITCH GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (PARTIAL) (BELOW DASH NEAR STEERING COLUMN) PPL/WHT WIRE PRESS CTRL SOLENOID RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN SERVICE ENGINE SOON INDICATOR TCC PWM SOL TCC PWM SOLENOID TCC/ STOP LAMPS SWITCH TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 17 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS TEMP SIG IN TWISTED WIRE PAIR VEHICLE CONTROL MODULE (CENTER FRONT OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VSS HI VSS LO YEL WIRE YEL/BLK WIRE

2-3 SHIFT SOL CTRL ANTI-LOCK BRAKE SYSTEM BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CAM POSIT SENS RTN FUEL LEV PPL CAMSHAFT POSITION (CMP) SENSOR (INTERNAL TO DISTRIBUTOR) CKP DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE GRY WIRE HALL EFFECT SENSOR IGN FEED KNOCK SENS SIG KNOCK SENSOR (KS) (TOP CENTER REAR OF ENGINE) LT BLU WIRE LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE NCA WIRE PNK PNK PNK 2 3 4 WIRE PNK WIRE PNK/BLK WIRE PPL PPL CKP SENS RTN VSS RTN VSS SIG PPL/WHT WIRE PURGE VENT CTRL RETURN SENSOR CKP SENSOR SIGNAL TAN WIRE TAN/WHT WIRE TANK PRESSURE SENSOR (TOP OF FUEL TANK) VEHICLE SPEED OUT VEHICLE SPEED SENSOR (VSS) (LEFT SIDE OF TRANSMISSION) WHL SPD SIG, LEFT FRT CAM POSIT SENS SIG WHT DK GRN/ WIRE WHT LT BLU/ WIRE WHT LT GRN/ WIRE WHT WIRE YEL WIRE YEL/BLK WIRE

3 4 5 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) FUEL GAUGE 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 (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP MAP REF LO MASS AIR FLOW SENSOR (MAF) (MOUNTED IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) NCA WIRE ORG/ WIRE PNK 6 7 8 9 10 11 12 13 14 15 WIRE PNK PNK PNK 2 3 4 5 WIRE PNK PNK WIRE PNK WIRE PPL RED WIRE RED/BLK WIRE REF LO REF THROTTLE POSITION (TP) SENSOR (ON THROTTLE BODY, TOP OF ENGINE) SENSOR BREAKOUT) SPEEDO- METER TACHO- METER TAN WIRE TEMP WHT WIRE YEL WIRE

3 4 5 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 BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE BULKHEAD GROMMET TOWARD IGNITION SW) CYLINDER 2 CYLINDER 1 CYLINDER 5 CYLINDER 3 CYLINDER 4 CYLINDER 6 DISTRIBUTOR (TOP REAR OF ENGINE) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-BAT FUSE 6 EGR VALVE CTRL ELECTRONIC BRAKE CONTROL MODULE FEED FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) GROUND GRY WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES HOT IN RUN I-3 FUSE 9 I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) IGN FEED IGNITION IGNITION COIL (TOP RIGHT SIDE OF ENGINE) IGNITION CONTROL MODULE (RIGHT TOP OF ENGINE, AT IGNITION COIL) LT BLU/WHT WIRE ORG/ WIRE PCS SOL (HI) INPUT SPD SENS SIG INPUT SPD SENS RTN TIMING CTRL SIG PCS SOL (LO) VCM GROUND VCM GROUND GROUND 451 451 470 PNK 6 7 8 9 10 11 12 13 14 15 WIRE PNK IGN FEED WIRE PNK WIRE PPL PPL (ENGINE HARN, 18 CM FROM BREAKOUT TO BULKHEAD CONN) PPL FUEL LEVEL PRESSURE SWITCH IN RANGE SIG "C" RED WIRE RED/ BLK WIRE RED/BLK WIRE SHIFT INTERLOCK SYSTEM PPL SPARK PLUGS TIMING CONTROL RETURN TIMING CONTROL SIGNAL) TORQUE CONVERTER CLUTCH, STOP LAMP SWITCH (AT BRAKE PEDAL SUPPPORT) TRANSMISSION INPUT SPEED SENSOR (ON LEFT SIDE OF TRNASMISSION, NEAR THE MIDDLE) WHT WIRE WHT/ BLU WIRE WHT/BLK WIRE

1226 1225 TR SWITCH C TR SWITCH B TR SWITCH A 2-3 SHIFT SOLENOID VALVE 27 28 29 30 31 PPL 379 (OR 420) A/C SYSTEM A/T A/T M/T ANTILOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BATTERY BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT (OR PPL) WIRE BRN/WHT WIRE CLOSURE SIGNAL BOOST SENSOR SIG PRESS CTRL SOL VLV LO CLUTCH PEDAL POSITION SWITCH (TOP OF CLUTCH PEDAL SUPORT) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK/ PNK WIRE ECT SIGNAL GRN WIRE GRY WIRE LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/WHT WIRE ORG/ WIRE ORG/BLK WIRE PNK PNK PPL 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND ON RELAY BRACKET) PPL PPL APP 2 GROUND APP 1 GROUND APP 1 SIG PPL CKP SEN GRD A/C REQUEST SIG PPL PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID VALVE RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SENSOR GND SOLENOID VALVE 1-2 SHIFT SOLID STATE TAN WIRE TAN/BLK WIRE TCC PWM SOLENOID VALVE TCC/ABS BRAKE SW STOPLAMP SWITCH TIMING STEPPER MTR (HIGH) TIMING STEPPER MTR (LOW) TIMING STEPPER MTR (LOW) TRANSMISSION OUTPUT SPEED SENSOR (LEFT SIDE OF TRANS- MISSION, NEAR THE MIDDLE) TRANSMISSION SPEED INPUT TRANSMISSION TEMPERATURE SENSOR WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

27 28 29 30 31 PPL 5 VOLT REF ACCELERATOR PEDAL POSITION MODULE (ATTACHED TO ACCELERATOR PEDAL) APP 1 SENSOR APP 2 SENSOR APP 3 SENSOR BLK WIRE BLU WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT WIRE CLOSURE GRD CLOSURE SIGNAL DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE 12 ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR, ON LOWER CROSSMEMBER) ENG 1 FUSE 15 ENGINE SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUEL SOL CTRL FUEL SOL HIGH FUEL SOL LOW FUEL SOLE- NOID FUEL SOLENOID DRIVER (ON SIDE OF FUEL INJECTION PUMP) GRN WIRE GRY WIRE HIGH LOW HIGH RES SIG HOT AT ALL TIMES HOT IN HOT IN RUN OR 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 LT PPL OPTICAL FUEL TEMPERATURE SENSOR (PART OF FUEL INJECTION PUMP ASSEMBLY) ORG/ WIRE ORG/BLK WIRE PNK PNK PPL 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE PPL PPL (ENG HARN, APPROX 32 CM FROM BREAKOUT FOR BATTERY JUNCTION BLOCK) PUMP CAM SIG RED WIRE RED/BLK WIRE RUN WIRE SENSOR GROUND STOP/HAZ FUSE 11 TAN WIRE TAN/BLK WIRE TORQUE CONVERTER CLUTCH (TCC), STOPLAMPS SWITCH (AT BRAKE PEDAL SUPPORT) TRANS FUSE 17 WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

A/T A/T M/T BLK WIRE BLK/WHT WIRE BLU WIRE BRN (OR LT BLU) WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-BAT FUSE 6 ENG BAT FUSE 10 FUEL HEATER (PART OF FUEL/WATER SEPARATOR) FUEL LIFT PUMP (INSIDE RIGHT FRAME RAIL) FUEL PUMP PRIME CONNECTOR (TAPED TO FUEL PUMP RELAY BREAKOUT) FUEL PUMP RELAY (ON ENGINE FIREWALL RELAY BRACKET, UNDER BATTERY JUNCTION BLOCK) GAUGES FUSE 8 GRN WIRE GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK INDICATOR INSTRUMENT CLUSTER LT BLU WIRE LT GRN WIRE M/T MALFUNCTION INDICATOR LAMP (MIL) ORG/ WIRE PNK FEDERAL WIRE PNK PNK WIRE PNK WIRE RED WIRE SERVICE THROTTLE SOON INDICATOR SPEED METER TAN WIRE WAIT TO WASTEGATE SOLENOID (TOP LEFT REAR OF ENG) WATER IN FUEL INDICATOR WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

"SERV THROTTLE SOON" IND A/C ENABLE GROUND GROUND 451 451 A/C SYSTEM A/T M/T ANTILOCK BRAKES SYSTEM BATTERY BATTERY WASTEGATE SOL CTRL BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CALIFORNIA CALIFORNIA DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ESO CTRL FUSIBLE LINK FUSIBLE LINK (22 GA-RUST) FUSIBLE LINKS GLOW PLUG CONTROLLER (LEFT REAR OF ENG, NEAR FIREWALL) GRD IGNITION GLOW PLUG SIG RLY CTRL PNK WIRE HOT AT ALL TIMES LEFT BANK GLOW PLUGS LT BLU WIRE LT GRN WIRE NCA WIRE ORG/ WIRE PNK IGNITION RLY CTRL GRD BATTERY GLOW PLUG OUT 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 ON RELAY BRACKET) PPL PPL GLOW PLUG OUT GLOW PLUG OUT GLOW PLUG OUT GLOW PLUG OUT RED WIRE RIGHT BANK GLOW PLUGS TAN WIRE WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE