GMC Pickup K2500 (1985-2000) lt grn 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 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 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

ABS FUSE ABS IND. BATTERY PUMP MOTOR GROUND BLK WIRE BLK/WHT WIRE BRAKE FUSE 18 BRAKE IND BRAKE PRESSURE WARNING SWITCH (UNDERSIDE OF EBCM) BRAKE SW OUTPUT BRN WIRE DAYTIME RUNNING LAMP (DRL) MODULE (BEHIND LEFT SIDE OF DASH) DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) ENGINE CONTROLS SYSTEM FRONT AXLE ACTUATOR (ON RIGHT REAR OF FRONT DRIVE AXLE) FUSE/RELAY BLOCK (LEFT REAR OF ENGINE COMPT) GAUGES FUSE 4 HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) IGNITION ABS IND GROUND BRAKE SW INPUT INSTRUMENT CLUSTER LEFT FRONT WHEEL SPEED SENSOR LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE M/T NEAR BREAKOUT TO TRANSFER CASE RELAY) PNK WIRE PPL PPL DATA LINK CONNECTOR (DLC) (LEFT OF STEERING COLUMN) PPL PPL 1807 680 PPL SERIAL DATA PPL/WHT WIRE RED WIRE RIGHT FRONT WHEEL SPEED SENSOR SENSOR LOW SENSOR LOW SENSOR HIGH SENSOR HIGH 830 872 STOPLAMP SWITCH (TOP OF BRAKE PEDAL) TAN WIRE TAN/WHT WIRE TRANSFER CASE CONTROL MODULE (ON STEERING COLUMN SUPPORT BRACKET) TRANSMISSIONS SYSTEM VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (VSS) (LEFT SIDE OF TRANSMISSION/ TRANSFER CASE) VEHICLE SPEED SIG VSS VSS SIG BRAKE LAMP IND OUT SERIAL DATA LINE BRAKE IND INPUT EBCM GROUND YEL WIRE YEL/BLK WIRE

3 22 SPEED SENSOR OUTPUT BLK WIRE BLK/WHT WIRE BLU WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION SWITCH (TOP OF CLUTCH PEDAL) CRUISE CONTROL MODULE (LEFT REAR OF ENGINE COMPARTMENT) CRUISE CONTROL SWITCH CRUISE ENGAGE INPUT CRUISE FUSE 6 CRUISE ON INPUT SET/COAST SIG RESUME/ACCEL SIG DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENGINE CONTROL SYSTEM EXTERIOR LIGHT SYSTEM GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE M/T A/T M/T A/T (I/P HARN, LEFT REAR OF ENGINE COMPT) OFF (OR ON (OR PNK) WIRE ORG/ WIRE PPL PPL SHIFT INTER- LOCK SYSTEM PPL/WHT WIRE STOP/HAZ FUSE 1 STOPLAMP SWITCH (TOP OF BRAKE PEDAL) VCM SIGNAL SPEED SENSOR INPUT VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (VSS) (LEFT SIDE OF TRANSMISSION) VSS HIGH VSS LOW WHT WIRE

2-HI IND 2-HI SW 4 LO INDIC CTRL 4 LO SW 4 LOW SELECT SW IN 2 HI SELECT SW IN 4 HI SELECT SW IN BATTERY IN 4-HI IND 4-HI SW 4-LO IND ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CHANNEL A CHANNEL B CHANNEL C CHANNEL P DATA LINK CONNECTOR (PARTIAL) (UNDER LEFT SIDE OF DASH) DIESEL DK BLU/WHT WIRE DK GRN/WHT WIRE ENGINE CONTROLS, CRUISE CONTROL, SOUND SYSTEMS, INSTRUMENT CLUSTER EXTERIOR LIGHTS FRONT AXLE ACTUATOR FRONT AXLE SWITCH FUSE 24 GASOLINE GAUGES FUSE 4 GROUND GROUND GROUND BATTERY IN BATTERY IN PNP SW-P/N IN GRY WIRE GRY/BLK WIRE HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) IGNITION IN ENCODER GROUND GROUND 2 HI INDIC CTRL 4 HI INDIC CTRL ILLUMINATION LAMP LOW SIG LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OUTPUT VSS PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) (BEHIND RIGHT SIDE OF DASH) PPL/WHT WIRE RED WIRE RED/WHT WIRE SIG AXLE SPARE POWER SOURCE AUXILIARY BATTERY RELAY TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANSFER CASE CONTROL MODULE (STEERING COLUMN BRACKET) TRANSFER CASE ENCODER (RIGHT SIDE CENTER OF TRANSFER CASE) TRANSFER CASE ENCODER MOTOR (RIGHT SIDE OF TRANSFER CASE) TRANSFER CASE SELECT SWITCH TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TURN B/U FUSE 16 VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR BUFFER (DIESEL) (RIGHT SIDE OF DASH) YEL WIRE YEL/BLK WIRE

2-HI IND 2-HI SW 4 LO INDIC CTRL 4 LO SW 4 LOW SELECT SW IN 2 HI SELECT SW IN 4 HI SELECT SW IN BATTERY IN 4-HI IND 4-HI SW 4-LO IND ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CHANNEL A CHANNEL B CHANNEL C CHANNEL P DATA LINK CONNECTOR (PARTIAL) (UNDER LEFT SIDE OF DASH) DIESEL DK BLU/WHT WIRE DK GRN/WHT WIRE ENGINE CONTROLS, CRUISE CONTROL, SOUND SYSTEMS, INSTRUMENT CLUSTER EXTERIOR LIGHTS FRONT AXLE ACTUATOR FRONT AXLE SWITCH FUSE 24 GASOLINE GAUGES FUSE 4 GROUND GROUND GROUND BATTERY IN BATTERY IN PNP SW-P/N IN GRY WIRE GRY/BLK WIRE HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) IGNITION IN ENCODER GROUND GROUND 2 HI INDIC CTRL 4 HI INDIC CTRL ILLUMINATION LAMP LOW SIG LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OUTPUT VSS PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) (BEHIND RIGHT SIDE OF DASH) PPL/WHT WIRE RED WIRE RED/WHT WIRE SIG AXLE SPARE POWER SOURCE AUXILIARY BATTERY RELAY TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANSFER CASE CONTROL MODULE (STEERING COLUMN BRACKET) TRANSFER CASE ENCODER (RIGHT SIDE CENTER OF TRANSFER CASE) TRANSFER CASE ENCODER MOTOR (RIGHT SIDE OF TRANSFER CASE) TRANSFER CASE SELECT SWITCH TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TURN B/U FUSE 16 VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR BUFFER (DIESEL) (RIGHT SIDE OF DASH) YEL WIRE YEL/BLK WIRE

10 11 PPL 2-3 SHIFT SOL CTRL AIR PUMP REL CTRL VSS SIG BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE BRN/WHT WIRE CAM POSIT SENS SIG CAMSHAFT POSITION SENSOR (INSIDE DISTRIBUTOR) DK (ENG HARN, 11 CM FROM EGR VALVE BREAKOUT) LT DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK WIRE FUEL LEVEL INPUT GRN WIRE IGN SENS SENS FEED SIG RTN INLINE GENDER ADAPTER KNOCK SENS SIG KNOCK SENSOR (KS) (LEFT) (LEFT SIDE OF ENGINE BLOCK, BELOW EXHAUST MANIFOLD) KNOCK SENSOR (KS) (RIGHT) (RIGHT SIDE OF ENGINE BLOCK, BELOW EXHAUST MANIFOLD) LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE LT LT LT PPL LT PPL/ (RIGHT FRONT SIDE OF ENG BLOCK) NCA WIRE OTHERS PNK IGNITION FEED WIRE PNK PNK 1 2 WIRE PNK PNK PNK PNK 3 4 5 6 WIRE PNK PPL WIRE PNK WIRE PNK/BLK WIRE PPL PPL PNK WIRE PPL PPL PPL SENSOR RETURN VSS RTN VSS SIGNAL CRANK POSIT SENS SIG PPL/WHT WIRE RED/BLK WIRE SENS RTN FUEL GAUGE LVL PPL SENSOR RETURN SENSOR SIGNAL TAN WIRE TAN/WHT WIRE VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT SIDE OF TRANSMISSION, LEFT SIDE OF VENT CTLR W/ DUAL FUEL TANKS WHT WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL LT 2-3 SHIFT SOLENOID AIR INJECTION REACTION PUMP CLUTCH (ON FRONT OF AIR PUMP) AIR INJECTION REACTION RELAY (UNDERHOOD FUSE/ RELAY CENTER) AUTOMATIC TRANSMISSION AUTOMATIC TRANSMISSION FLUID PRESSURE (TFP) MANUAL VALVE POSITION SWITCH BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE EXHAUST GAS RECIRCULATION (EGR) VALVE (ON TOP LEFT SIDE OF ENG) FLUID TEMPERATURE SENSOR FUEL INJ 1 FUEL INJ 2 FUEL INJ 3 FUEL INJ 4 FUEL INJ 5 FUEL INJ 6 FUEL INJ 7 FUSE GRN WIRE GRY WIRE HOT IN RUN, START LT BLU WIRE LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT PNK WIRE NCA WIRE ORG/ WIRE PNK FUEL INJ 8 WIRE PNK PNK PNK 1 2 3 4 5 WIRE PNK PNK PNK PNK 3 4 5 6 WIRE PNK PNK PNK PNK PNK WIRE PNK PNK WIRE PNK PPL WIRE PNK WIRE PNK/BLK WIRE PPL PPL LT PPL/WHT WIRE PRESSURE CONTROL SOLENOID VALVE RED WIRE RED/BLK WIRE TAN WIRE TORQUE CONVERTOR CLUTCH PULSE WIDTH MODULATION SOLENOID UNDERHOOD FUSE/RELAY CENTER WHT WIRE YEL WIRE YEL/BLK WIRE