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

2-3 SHIFT SOL CTRL 1-2 SHIFT SOL CTRL DIAGNOSTIC TEST 9 6 DATA LINK CONNECTOR (PARTIAL) (BELOW DASH, NEAR STEERING COLUMN) A/T INPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) A/T OUTPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) AUTOMATIC TRANSMISSION BAROMETRIC PRESSURE SENSOR (TOP LEFT REAR OF INTAKE MANIFOLD) BATTERY FEED BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE SIGNAL TCC PWM CONTROL BRN WIRE DK BLU 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 (REAR OF INTAKE MANIFOLD) 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 OSS INPUTS OUT PCS HI PCS LO IGNITION PNK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C RED WIRE RED/BLK WIRE RUN WIRE SERVICE TRANS IND SERIAL DATA SERVICE TRANSMISSION INDICATOR SYSTEM GROUND SYSTEM GROUND SENSOR GROUND 5 VOLTS REF TAN WIRE TCC PWM SOL 1-2 SHIFT SOL 2-3 SHIFT SOL THROTTLE POSITION SENSOR (RIGHT SIDE OF FUEL INJECTION PUMP) TORQUE CONVERTER CLUTCH, STOPLAMP SWITCH TRANS FLUID TEMP SIG BARO SENSOR INPUT TRANS FUSE 17 TRANSMISSION CONTROL MODULE (LEFT SIDE OF DRIVER'S ISLAND) TRANSMISSION TEMPERATURE SENSOR VEHICLE SPEED INPUT INPUT SPEED SENS LO INPUT SPEED SENS HI VEHICLE SPEED SENSOR CALIBRATOR VEHICLE SPD OUTPUT WHT WIRE WHT/BLK 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

ACCY BATTERY BATTERY JUNCTION BLOCK (LEFT REAR OF ENGINE COMPT) BLK (OR WIRE BLK WIRE BULB TEST CHARGING CIRCUIT DIESEL DK BLU WIRE ENGINE CONTROLS (GLOW PLUGS) FUSIBLE LINK (16 GA- FUSIBLE LINK (16 GA- FUSIBLE LINK (10 GA- RUST) GAS GRY WIRE HOLD- IN COIL I/P FUSE BLOCK (BEHIND DASH PANEL) CRANK FUSE 18 IGNITION SWITCH LOCK M/T A/T OFF PPL PPL DIESEL PPL PPL PPL PPL (ENGINE HARN, NEAR LEFT FIREWALL GROMMET) PULL- IN COIL RED WIRE RUN WIRE SECONDARY BATTERY (DIESEL) STARTER MOTOR STARTER RELAY (ON ENGINE FIREWALL RELAY BRACKET) STARTER SOLENOID WHT WIRE YEL 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 SHUTOFF 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 HAZARD LAMPS FLASHER (INNER LEFT SIDE STEERING COLUMN SUPPORT BRACKET) 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 (I/P SIDE OF ENG HARN, 8 CM FROM BREAKOUT FOR TURN SIGNAL SWITCH CONNECTOR) PUMP CAM SIG RED WIRE RED/BLK WIRE RUN WIRE SENSOR GROUND STOP LAMP SWITCH (AT BRAKE PEDAL SUPPORT) 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