GMC Pickup C2500 (1985-2000) gry Wiring diagrams

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C COMPRESSOR CYCLING SWITCH (IN LOW PRESSURE LINE, ON ACCUMULATOR) A/C CTRL A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C REQ AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (EXC 4.3L) (IN UNDERHOOD FUSE/RELAY CENTER) BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLK/WHT WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FRONT MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE GRY/BLK WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 HVAC CONTROL MODULE IGN E FUSE A/C COMP FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE PPL REAR DEFOGGER SYSTEM RED WIRE SW SIG SW SIG RELAY CTRL TAN WIRE UNDERHOOD FUSE-RELAY CENTER VALVE CTRL AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) WATER VALVE (SUBURBAN, UTILITY, CREW CAB ONLY) (RIGHT CENTER OF INTAKE AREA) WHT WIRE YEL WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 3-2 CTRL SOLENOID 3-2 DOWNSHIFT SOL AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU WIRE BRAKE FUSE 18 BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DASH FUSE BLOCK DATA CLASS II DK BLU WIRE ECM 1 FUSE ECM-B FUSE ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP RIGHT FRONT OF ENGINE) FRONT WHEEL LOCK FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN OFF, RUN OR START HOT IN RUN HOT IN RUN OR START IGNITION IN INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK PNK WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL HI SOLENOID LO RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN STOPLAMP SWITCH (ON BRAKE PEDAL BRACKET) TAN WIRE TAN/BLK WIRE TCC PWM SOL TCC PWM SOLENOID TCC SOL TCC SOLENOID THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS RANGE SWITCHES TRANS TEMP SIG IN TRANSFER CASE CIRCUIT PNK WIRE TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR VEHICLE SPEED SENSOR ADAPTOR VSS HI VSS LO WHT WIRE YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C COMPRESSOR CYCLING SWITCH (IN LOW PRESSURE LINE, ON ACCUMULATOR) A/C CTRL A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C REQ AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (EXC 4.3L) (IN UNDERHOOD FUSE/RELAY CENTER) BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLK/WHT WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FRONT MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE GRY/BLK WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 HVAC CONTROL MODULE IGN E FUSE A/C COMP FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE PPL REAR DEFOGGER SYSTEM RED WIRE SW SIG SW SIG RELAY CTRL TAN WIRE UNDERHOOD FUSE-RELAY CENTER VALVE CTRL AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) WATER VALVE (SUBURBAN, UTILITY, CREW CAB ONLY) (RIGHT CENTER OF INTAKE AREA) WHT WIRE YEL WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 3-2 CTRL SOLENOID 3-2 DOWNSHIFT SOL AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU WIRE BRAKE FUSE 18 BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DASH FUSE BLOCK DATA CLASS II DK BLU WIRE ECM 1 FUSE ECM-B FUSE ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP RIGHT FRONT OF ENGINE) FRONT WHEEL LOCK FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN OFF, RUN OR START HOT IN RUN HOT IN RUN OR START IGNITION IN INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK PNK WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL HI SOLENOID LO RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN STOPLAMP SWITCH (ON BRAKE PEDAL BRACKET) TAN WIRE TAN/BLK WIRE TCC PWM SOL TCC PWM SOLENOID TCC SOL TCC SOLENOID THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS RANGE SWITCHES TRANS TEMP SIG IN TRANSFER CASE CIRCUIT PNK WIRE TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR VEHICLE SPEED SENSOR ADAPTOR VSS HI VSS LO WHT WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/T ISS HI IN A/T ISS LO IN AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRAKE SWITCH ASSEMBLY (ON BRAKE PEDAL BRACKET) BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE ECM 1 FUSE ECM-B FUSE ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE ENG 1 FUSE FRONT WHEEL LOCK FUEL INJECTORS, IGNITION CONTROL MOUDULE, IGNITION COIL FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HEADLAMP, PANEL DIMMER SWITCH PNK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LEFT REAR SIDE LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MAF SENSOR, HEATED OXYGEN SENSORS MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL HI SOLENOID LO RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN TAN WIRE TCC PWM SOL TCC PWM SOLENOID THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS RANGE SWITCHES TRANS TEMP SIG IN TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR VEHICLE SPEED SENSOR ADAPTOR VSS HI VSS LO YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMP FUSE A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C COMPRESSOR CYCLING SWITCH (IN LOW PRESSURE LINE, ON ACCUMULATOR) A/C CTRL A/C ENABLE A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER FUSE 3 BLOWER MOTOR BLOWER RESISTOR (UNDER RIGHT SIDE OF DASH, ON HEATER HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FRONT MODE DOOR MOTOR (UNDER DASH ON HEATER- A/C CASE) FUSE BLOCK GRY WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER DASH ON TOP OF HEATER-A/C CASE) HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 IGN 1 FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (LEFT REAR OF ENGINE COMPT) PPL REAR DEFOGGER SYSTEM RED WIRE TAN WIRE WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMP FUSE A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C COMPRESSOR CYCLING SWITCH (IN LOW PRESSURE LINE, ON ACCUMULATOR) A/C CTRL A/C ENABLE A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER FUSE 3 BLOWER MOTOR BLOWER RESISTOR (UNDER RIGHT SIDE OF DASH, ON HEATER HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FRONT MODE DOOR MOTOR (UNDER DASH ON HEATER- A/C CASE) FUSE BLOCK GRY WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER DASH ON TOP OF HEATER-A/C CASE) HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 IGN 1 FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (LEFT REAR OF ENGINE COMPT) PPL REAR DEFOGGER SYSTEM RED WIRE TAN WIRE WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND AIR TEMP DR SENSOR MODE SIGNAL BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH BRN WIRE DK BLU WIRE DK GRN WIRE FRONT MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FRONT TEMPERATURE DOOR MOTOR FUSE BLOCK GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C- HEATER BLOWER HOUSING) HOT AT ALL TIMES HOT IN RUN HTR A/C FUSE 12 HVAC CONTROL MODULE LT BLU WIRE OFF LO ORG/ WIRE PPL REAR DEFOGGER SYSTEM RECIRC CTRL IGNITION RECIRCULATION DOOR MOTOR RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND AIR TEMP DR SENSOR MODE SIGNAL BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH BRN WIRE DK BLU WIRE DK GRN WIRE FRONT MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FRONT TEMPERATURE DOOR MOTOR FUSE BLOCK GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C- HEATER BLOWER HOUSING) HOT AT ALL TIMES HOT IN RUN HTR A/C FUSE 12 HVAC CONTROL MODULE LT BLU WIRE OFF LO ORG/ WIRE PPL REAR DEFOGGER SYSTEM RECIRC CTRL IGNITION RECIRCULATION DOOR MOTOR RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL WIRE

260 (CROSS BODY HARNESS, 4 DOOR 4-DOOR 2-DOOR 640 (OR 540) 1576 (OR 56) 294 39 157 1455 150 195 156 BLK (OR BLK/WHT) WIRE BLK WIRE BLK/WHT WIRE CARGO DOOR JAMB SWITCH CARGO DOOR LOCK SWITCH (W/ CARGO DOORS) CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DATA LINK INTERIOR CONNECTOR LAMPS (UNDER LEFT SYSTEM SIDE OF DASH) DOOR LOCK CONTROL MODULE (FRONT OF LEFT REAR WHEELWELL) DOOR LOCK RELAY (UNDER CENTER OF DASH, NEAR REMOTE CONTROL DOOR LOCK RECEIVER) GAUGES FUSE 4 GROUND DOOR JAMB SW LOCK SIG UNLOCK SIG PPL GRY WIRE HORNS SYSTEM HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT SIDE OF DASH, LEFT FRONT DOOR JAMB SWITCH LEFT FRONT DOOR LOCK ACTUATOR LEFT FRONT DOOR LOCK SWITCH LEFT REAR DOOR JAMB SWITCH LEFT REAR DOOR LOCK ACTUATOR LOCK LT BLU WIRE LUXURY ORG/ WIRE ORG/BLK WIRE PNK WIRE PPL PWR-ACCY CIRCUIT BREAKER REAR CARGO DOOR LOCK ACTUATOR (CARGO DOORS) REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR JAMB SWITCH RIGHT FRONT DOOR LOCK ACTUATOR RIGHT FRONT DOOR LOCK SWITCH RIGHT REAR CARGO DOOR CONTACTOR (RIGHT REAR DOOR JAMB) RIGHT REAR DOOR JAMB SWITCH RIGHT REAR DOOR LOCK ACTUATOR RR DOOR SW BATT (B+) SEAT BELT SWITCH BREAKOUT) SUBURBAN/ UTILITY TAN WIRE TRUNK, TAIL- GATE, FUEL DOORS SYSTEM UNLOCK UTILITY W/ REAR CARGO DOORS UTILITY W/ REAR LIFTGATE W/ CARGO DOORS W/ LIFTGATE W/ CARGO DOORS W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE