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

1-3 FUSE 9 A/T ISS HIGH A/T ISS LOW AUTOMATIC TRANSMISSION SHAFT SPEED SENSOR (A/T ISS) (LEFT SIDE OF TRANSMISSION) BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRN WIRE CRUISE CONTROL MODULE (ON LEFT RADIATOR SUPPORT BRACKET) CRUISE CONTROL SWITCH CRUISE ENGAGED IN VSS INPUT DK BLU WIRE DK GRN/WHT WIRE GRY WIRE GRY/BLK WIRE HAZARD LAMPS FLASHER (LEFT OF STEERING COLUMN) HOT AT ALL TIMES HOT IN RUN I/P FUSE BLOCK LT BLU WIRE LT BLU/BLK WIRE NCA WIRE OFF ORG/ WIRE PPL R/A RED/BLK WIRE RESISTOR (ENGINE HARNESS, 7 CM FROM BREAKOUT TO ENGINE COOLANT FAN MOTOR CONN) S/C STOP/HAZ FUSE 1 STOPLAMPS SWITCH (ABOVE BRAKE PEDAL) TORQUE CONVERTER CLUTCH, STOPLAMPS SWITCH (ABOVE BRAKE PEDAL) VEHICLE CONTROL MODULE (VCM) (ON LEFT RADIATOR SUPPORT BRACKET) VSS OUTPUT CRUISE ENGAGED

1-3 FUSE 9 A/T ISS HIGH A/T ISS LOW AUTOMATIC TRANSMISSION SHAFT SPEED SENSOR (A/T ISS) (LEFT SIDE OF TRANSMISSION) BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRN WIRE CRUISE CONTROL MODULE (ON LEFT RADIATOR SUPPORT BRACKET) CRUISE CONTROL SWITCH CRUISE ENGAGED IN VSS INPUT DK BLU WIRE DK GRN/WHT WIRE GRY WIRE GRY/BLK WIRE HAZARD LAMPS FLASHER (LEFT OF STEERING COLUMN) HOT AT ALL TIMES HOT IN RUN I/P FUSE BLOCK LT BLU WIRE LT BLU/BLK WIRE NCA WIRE OFF ORG/ WIRE PPL R/A RED/BLK WIRE RESISTOR (ENGINE HARNESS, 7 CM FROM BREAKOUT TO ENGINE COOLANT FAN MOTOR CONN) S/C STOP/HAZ FUSE 1 STOPLAMPS SWITCH (ABOVE BRAKE PEDAL) TORQUE CONVERTER CLUTCH, STOPLAMPS SWITCH (ABOVE BRAKE PEDAL) VEHICLE CONTROL MODULE (VCM) (ON LEFT RADIATOR SUPPORT BRACKET) VSS OUTPUT CRUISE ENGAGED

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 1223 1222 2-3 SHIFT SOL CTRL 1-2 SHIFT SOL CTRL DIAGNOSTIC TEST 1227 433 TRANS FLUID TEMP SIG BARO SENSOR INPUT 9 6 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) A/T INPUT SPEED SENSOR (LEFT FRONT SIDE OF TRANSMISSION) AUTOMATIC TRANSMISSION BAROMETRIC PRESSURE SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DRL MODULE, DRL RELAY, GENERATOR ECM 1 FUSE 12 ECM-BAT FUSE 6 ELECTRONIC BRAKE CONTROL MODULE ENGINE OIL PRESSURE INDICATOR SENSOR, FUEL PUMP RELAY ENGINE SPEED SENSOR (IN FUEL INJECTION PUMP) ENGINE SPEED SIGNAL SENSOR GROUND TP SENSOR INPUT FUEL INJECTION PUMP SHUTOFF SOLENOID,, FUEL PUMP RELAY GAUGES FUSE 8 GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK IGN BUSS INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OUT PCS HI PCS LO IGNITION PNK WIRE PNK RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C WIRE PNK WIRE PPL PPL BRAKE SIGNAL TCC PWM CONTROL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RUN WIRE SERVICE TRANS OUTPUT SERIAL DATA SERVICE TRANSMISSION INDICATOR STOP LAMPS, TORQUE CONVERTER BRAKE SWITCH SYSTEM GROUND SYSTEM GROUND 452 416 SENSOR GROUND 5 VOLTS REF TAN WIRE TCC PWM SOL 2-3 SHIFT SOL THROTTLE POSITION SENSOR (ON FUEL INJECTION PUMP) TRANS FUSE 17 TRANSMISSION CONTROL MODULE (LEFT INTERIOR FIREWALL) TRANSMISSION TEMPERATURE SENSOR VEHICLE SPEED INPUT INPUT SPEED SENS LO INPUT SPEED SENS HI VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER VEHICLE SPD OUTPUT VSS INPUTS WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

BRN WIRE DK GRN WIRE HOT IN I/P FUSE BLOCK LT GRN WIRE PARK/NEUTRAL POSITION (PNP), BACKUP LAMP SWITCH (LEFT SIDE OF TRANSMISSION) PROVISION FOR BACKUP LAMPS (ON LEFT FRAME RAIL NEAR REAR LAMP HARNESS) PROVISION FOR REAR MOUNTED CAMERA (NEAR BREAKOUT FOR STEERING COLUMN HARNESS) RUN WIRE TURN B/U FUSE 5 TURN SIGNAL FLASHER (I/P FUSE BLOCK)

7.4L BACKUP LAMPS CIRCUIT BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE COOLING FAN NOTOR HARN BREAKOUT) CRUISE CONTROL SYSTEM DK BLU WIRE DK GRN WIRE ENGINE CONTROLS SYSTEM GRN WIRE HAZARD HAZARD LAMPS FLASHER (INNER LEFT SIDE OF MAIN SUPPORT BRACKET) HEAD OFF HEADLAMP BREAKOUT) HEADLAMP SWITCH CONNECTOR) HEADLAMPS SWITCH HOT AT ALL TIMES HOT IN I/P FUSE BLOCK INSTRUMENT CLUSTER RIGHT TURN INDIC INTERIOR LAMPS SYSTEM LEFT FRONT PARK, TURN SIGNAL (T/S) LAMP LEFT FRONT SIDE MARKER LAMP LEFT HEAD- LAMP BREAKOUT) LEFT HEADLAMP BREAKOUT) LEFT REAR SIDE MARKER LAMP LEFT TURN INDIC LT BLU WIRE NCA WIRE NORMAL ORG/ WIRE PARK PARK TURN PPL PROVISION FOR CENTER HIGH MOUNTED STOP LAMP PROVISIONS FOR LEFT TAIL, STOP, TURN SIGNAL (T/S) LAMPS PROVISIONS FOR MARKER LAMPS PROVISIONS FOR RIGHT TAIL, STOP, TURN SIGNAL (T/S) LAMPS RIGHT FRONT PARK, TURN SIGNAL (T/S) LAMP RIGHT FRONT SIDE MARKER LAMP RIGHT REAR SIDE MARKER LAMP RIGHT REAR LICENSE LAMP LEFT REAR LICENSE LAMP RUN WIRE STOP-HAZ FUSE 11 TAIL LAMPS FUSE 7 TORQUE CONVERTER CLUTCH, STOP LAMPS SWITCH (BRAKE PEDAL SUPPORT BRACKET) TURN TURN B/U FUSE 5 TURN LEFT TURN RIGHT TURN SIGNAL FLASHER TURN SIGNAL SWITCH WHT WIRE WINDSHIELD WIPER MOTOR BREAKOUT) YEL 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

5-VOLT 6 9 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) BAROMETRIC PRESSURE (BARO) SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE EBCM ECM 1 FUSE 12 ECM-BAT FUSE 6 ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR, ON LOWER CROSSMEMBER) ENG SPEED SENS IN SENSOR RETURN TP SENS SIG ENGINE SPEED SENSOR (REAR OF INTAKE MANIFOLD, NEAR FUEL FILTER) GROUND GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I-3 FUSE 9 I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) IGN FEED LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE PNK 3 4 5 6 7 8 WIRE PNK WIRE PPL PPL BRAKE PEDAL SW IN TCC PWM SOL CTRL PPL STOPLMP SW IN PPL/WHT WIRE PRESS CTRL SOL (LO) IGN FEED PNK WIRE PRESS CTRL SOL. HI RED WIRE RED/BLK WIRE REF RTN SENSOR SERVICE TRANS OUT SERIAL DATA SIG TAN WIRE TCM GROUND TCM GROUND SENSOR RETURN TFT SIG BARO PRESS SENS SIG THROTTLE POSITION SENSOR (TPS) (RIGHT SIDE OF FUEL INJECTION PUMP) TO GLOWPLUG CONTROLLER) VEHICLE SPEED SENSOR (VSS) (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED SIG SPEED SENSOR SPEED SENSOR VSS VSS INPUT VSS OUT VSS RTN VSS SIG WHT WIRE YEL/BLK WIRE

"WAIT TO START" GLOW PLUGS 1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID A/T AUTOMATIC TRANSMISSION (REAR OF ENGINE) BLK WIRE BLK/WHT WIRE BRN WIRE DK BLU WIRE DK GRN WIRE ECM 1 FUSE 12 ECM-BAT FUSE 6 FUEL INJECTION PUMP SHUT-OFF SOLENOID (AT FUEL INJECTION PUMP) FUEL LIFT PUMP (ON INSIDE RIGHT FRAME RAIL) FUEL PUMP RELAY (ON ENGINE FIREWALL BRACKET, UNDER BATTERY JUNCTION BLOCK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE M/T NCA WIRE ORN/ PNK 3 4 5 6 7 8 WIRE PNK WIRE PRESSURE CONTROL SOLENOID RED WIRE RED/BLK WIRE SERVICE TRANS SPEEDO- METER TCC PWM SOLENOID TRANS FUSE 17 TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR TRANSMISSION RANGE (TR) PRESSURE SWITCH ASSEMBLY WATER IN FUEL WHT WIRE YEL WIRE YEL/BLK WIRE

A/T A/T M/T BATTERY FEED BATTERY JUNCTION BLOCK (ON LEFT REAR OF ENG COMPT) BLK WIRE BLU WIRE BRN WIRE CRANK FUSE (UPPER RIGHT SIDE OF STEERING COLUMN SUPPORT) DK BLU WIRE ENG 1 FUSE 15 FUEL HEATER (REAR OF INTAKE MANIFOLD, PART OF FUEL/ WATER SEPARATOR) FUEL INJECTION PUMP COLD ADVANCE SOLENOID (AT FUEL INJECTION PUMP) FUSIBLE LINK FUSIBLE LINK (12 GA- FUSIBLE LINK (16 GA- FUSIBLE LINK (22 GA-RUST) FUSIBLE LINKS GLOW PLUG CONTROLLER (LEFT REAR OF ENG, NEAR FIREWALL) GLOW PLUG CTRL GLOW PLUG OUT GROUND HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) IDLE SPEED CONTROL ACTUATOR SOLENOID (ON BRACKET ON FRONT FUEL INJECTION PUMP) IGN FEED IND LAMP OUT GROUND IGNITION SWITCH LEFT BANK GLOW PLUGS LOCK OFF LT GRN/BLK WIRE NOT USED STARTER FEED ORG/ WIRE PNK IGN FEED WIRE PNK WIRE PPL PPL PPL PPL S STUD RED WIRE RIGHT BANK GLOW PLUGS RUN WIRE STARTER RELAY (ON ENG FIREWALL RELAY BRACKET, UNDER BATTERY JUNCTION BLOCK) STARTER SOLENOID (ON STARTER, AT LOWER RIGHT SIDE OF ENGINE) STUD WATER IN FUEL INDICATOR SENSOR WHT WIRE YEL WIRE YEL/BLK WIRE