GMC Forward Control P3500 (1985-1999) range mode selector Wiring diagrams

2-3 SHIFT SOL BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN/BLK (OR DK GRN/YEL) WIRE ECM BAT FUSE ECM-CRNK FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMP SENS (TOP RIGHT SIDE OF ENG) FUSE BLOCK TRANS FUSE GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE ORG/ WIRE ORG/BLK (OR ORG) WIRE PNK WIRE PNK/BLK (OR BRN) WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE TCC SOL 1-2 SHIFT SOL TCC/BRAKE SWITCH (ON BRAKE PEDAL SUPPORT ARM) THROTTLE POSITION SENSOR (TOP RIGHT SIDE OF ENG) TRANS- MISSION INPUT SPEED SENSOR (LEFT FRNT OF TRANS) TRANS- MISSION TEMP VEHICLE SPEED SENSOR (REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

2-3 SHIFT SOL BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN/BLK (OR DK GRN/YEL) WIRE ECM BAT FUSE ECM-CRNK FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMP SENS (TOP RIGHT SIDE OF ENG) FUSE BLOCK TRANS FUSE GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE ORG/ WIRE ORG/BLK (OR ORG) WIRE PNK WIRE PNK/BLK (OR BRN) WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF SHIPPING PANEL) PPL PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE TCC SOL 1-2 SHIFT SOL TCC/BRAKE SWITCH (ON BRAKE PEDAL SUPPORT ARM) THROTTLE POSITION SENSOR (TOP RIGHT SIDE OF ENG) TRANS- MISSION INPUT SPEED SENSOR (LEFT FRNT OF TRANS) TRANS- MISSION TEMP VEHICLE SPEED SENSOR (REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1227 433 TRANS FLUID TEMP SIG BARO SENSOR INPUT 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 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 DASH FUSE BLOCK DK BLU WIRE DK BLU/WHT WIRE ECM 1 FUSE ECM BAT FUSE ENGINE SPEED SENSOR (IN FUEL INJECTION PUMP) ENGINE SPEED SIGNAL SENSOR GROUND TP SENSOR INPUT GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN HOT IN RUN OR START I-3 FUSE 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 (RIGHT SIDE OF FUEL INJECTION PUMP) TRANS FUSE TRANSMISSION CONTROL MODULE (LEFT INTERIOR FIREWALL) TRANSMISSION TEMPERATURE SENSOR VEHICLE SPD OUTPUT VEHICLE SPEED INPUT INPUT SPEED SENS LO INPUT SPEED SENS HI VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER VEHICLE SPEED SENSOR BUFFER, FUEL INJECTION PUMP FUEL SHUT OFF SOLENOID PNK WIRE VSS INPUTS WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

1 2 PPL 1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD 4.3L 5.7L AND 7.4L B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ECM BAT FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (NO LOCATION AVAILABLE) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST MANIFOLD) HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL/BLK WIRE

1 2 PPL 1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD 4.3L 5.7L AND 7.4L B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ECM BAT FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (NO LOCATION AVAILABLE) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST MANIFOLD) HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL/BLK WIRE

1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP FUSE FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (TOP OF COWL) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE PNK WIRE PNK/BLK WIRE PPL PPL 3 4 PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TAN/BLK WIRE TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL/BLK WIRE

12 13 PNK WIRE 1222 1224 1225 1226 1350 PNK WIRE 2-3 SHIFT SOL CTRL FUEL INJ CTRL 4 WHEEL DRIVE LOW SWITCH 999 998 961 452 PPL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCELERATOR BRACKET) APP 1 SENSOR APP 2 SENSOR APP 3 SENSOR B/H BATTERY FEED 4 WHL LOW SW BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE CRUISE CONTROL SYSTEM CRUISE ON/OFF SIG DATA LINK CONNECTOR (NO LOCATION AVAILABLE) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/BLK WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENG SHUT-OFF CTRL ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) ENGINE GROUND (NO LOCATION AVAILABLE) ENGINE SHUT- OFF SOLENOID (TOP FRONT OF ENGINE) FUEL INJ CTRL FUEL SOLENOID (TOP FRONT OF ENGINE) FUEL SOLENOID DRIVER (TOP FRONT FUSE BLOCK FUSIBLE LINK (NO LOCATION AVAILABLE) GRY WIRE GRY/BLK WIRE GRY/RED WIRE HI RESOLUTION SIG HOT AT ALL TIMES HOT IN RUN OR START LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE OF ENGINE) OPTICAL SENSOR AND FUEL TEMPER- ATURE SENSOR (TOP FRONT OF ENGINE) ORG/ WIRE ORG/BLK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (LEFT SIDE OF DRIVER'S ISLAND) PPL PPL 15 16 PRESSURE CONTROL SOL RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RESUME/ACCEL SIG SET/COAST SIG SYSTEM GND CLOSURE GRD APP 2 SENS GND APP 1 SENS GND APP 3 SENS GND SENSOR GND TAN WIRE TCC BRAKE SW TCC SOL 2-3 SHIFT SOL 1-2 SHIFT SOL TRANS FLUID TEMP (TFT) SENSOR TRANS FUSE TRANS INPUT SPD LO CKP SIG OPTICAL SENS GND OPTICAL SENS CAM SIG TRANS OUTPUT TRANSMISSION INPUT SPEED SENSOR VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (NO LOCATION AVAILABLE) VSS VSS INPUT VSS OUTPUT WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

"TRANS" LAMP 1-2 SHIFT SOL 2-3 SHIFT SOL TCC SOL 2-3 SHIFT SOL CTRL 1-2 SHIFT SOL CTRL DIAGNOSTIC TEST A/C INPUT BRAKE SIGNAL TCC CONTROL PPL ACCY AIR CONDI- TIONING SYSTEM ALT FUSE B/H BATTERY FEED BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BLU WIRE BRN WIRE BULB TEST COLD ADVANCE FAST IDLE TEMPERATURE SWITCH (RIGHT REAR OF ENGINE) COLD ADVANCE SOLENOID (TOP FRONT OF ENGINE) DATA LINK CONNECTOR (BEHIND LEFT SIDE SHIPPING DIODE (BEHIND GENERATOR) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ECM BAT FUSE ECM CRANK FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE SPEED SIGNAL SENSOR GROUND TP SENSOR INPUT FAST IDLE SOLENOID (TOP LEFT SIDE OF ENGINE) FUEL HEATER (TOP REAR OF ENGINE) FUEL SHUT- OFF SOLENOID (TOP FRONT OF ENGINE) FUSE BLOCK FUSIBLE LINK (20 GA-RUST) FUSIBLE LINKS GLOW PLUG CONTROLLER (LEFT SIDE OF ENGINE) GLOW PLUG WAIT LAMP GRY WIRE GRY/BLK WIRE GRY/RED WIRE HOT AT ALL TIMES HOT AT ALL TIMES FUSIBLE LINK HOT IN CRANK HOT IN RUN, BULB TEST OR START INPUTS INSTRUMENT CLUSTER LEFT BANK GLOW PLUGS LOCK OFF LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE ORG/BLK WIRE PANEL) PCS HI PCS LO IGNITION PNK RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C WIRE PNK WIRE PNK/BLK WIRE PPL PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RIGHT BANK GLOW PLUGS RUN WIRE SERVICE TRANS OUTPUT SERIAL DATA SYSTEM GROUND SYSTEM GROUND 452 416 SENSOR GROUND 5 VOLTS REF TAN/BLK WIRE TCC/BRAKE SWITCH (ON BRAKE PEDAL SUPPORT) TRANS FLUID TEMP SIG MAP SENS TRANS FUSE TRANS- MISSION FLUID TEMP (TFT) SENSOR TRANSMISSION CONTROL MODULE (TCM) (BEHIND LEFT SIDE OF SHIPPING PANEL) TRANSMISSION INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED INPUT TRANS INPUT SPD LO TRANS INPUT SPD HI VEHICLE SPEED SENSOR (REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT SIDE OF I/P) VEHICLE SPD OUTPUT VSS WATER IN FUEL INDICATOR WATER-IN FUEL SENSOR (TOP REAR OF ENGINE) WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

1 2 PPL 1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD 4.3L 5.7L AND 7.4L B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ECM BAT FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (NO LOCATION AVAILABLE) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST MANIFOLD) HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE OXYGEN SENSOR (IN EXHAUST MANIFOLD) PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL/BLK WIRE

1-2 SHIFT SOLENIOD 2-3 SHIFT SOLENIOD B/H CONN BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (BEHIND LEFT SIDE OF SHIPPING PANEL) DK BLU WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER (IN FUEL TANK) FUEL PUMP FUSE FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE) FUEL PUMP PRIME CONNECTOR (TOP OF COWL) FUEL PUMP RELAY (LOWER LEFT SIDE OF SHIPPING PANEL) FUSE BLOCK GRY WIRE HOT AT ALL TIMES LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE ORG/ WIRE PNK WIRE PNK/BLK WIRE PPL PPL 3 4 PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SOLENOID TAN/BLK WIRE TORQUE CONVERTER CLUTCH TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF I/P) WHT/BLK WIRE YEL/BLK WIRE