GMC Pickup K2500 (1985-2000) yel 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 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

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

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

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

16 PPL AUTOMATIC TRANSMISSION INPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) AUX TANK FUEL LVL SIG AUXILIARY FUEL TANK LEVEL SENSOR (IN FUEL TANK) BALANCE FUEL PUMP (ON INSIDE LEFT FRAME RAIL NEAR FRONT OF REAR TANK) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF DASH) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FUEL GAUGE INPUT FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE OF FRAME RAIL) FUEL PUMP BALANCE RELAY (ON FUEL PUMP BALANCE MODULE) FUEL PUMP MODULE (W/ DUAL FUEL TANKS) FUEL PUMP, SENDER (W/O DUAL FUEL TANKS) (IN FUEL TANK) FUEL TANK PRESSURE SENSOR (IN FUEL TANK) (CALIFORNIA) GAUGES FUSE 4 GRN WIRE GROUND GRY WIRE HOT IN OFF, RUN OR START HOT IN RUN OR START HOT IN RUN OR START UNDERHOOD FUSE/RELAY CENTER I/P FUSE BLOCK IGN E FUSE INPUT INSTRUMENT CLUSTER INTAKE AIR TEMPERATURE SENSOR (IN AIR INTAKE DUCT) LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP RIGHT FRONT OF ENGINE) MASS AIR FLOW SENSOR (IN AIR INTAKE DUCT) OUTPUT TO GAUGE PNK IGNITION WIRE PNK PNK PNK WIRE PNK WIRE PPL PPL/WHT WIRE PRIMARY TANK FUEL LVL SIG RED WIRE RED/BLK WIRE RELAY CTRL SERVICE ENGINE SOON INDICATOR SPEEDOMETER TACHOMETER TAN WIRE THROTTLE POSITION SENSOR (ON THROTTLE BODY ASSEMBLY) TRANS FUSE 20 W/ DUAL FUEL TANKS W/O DUAL FUEL TANK W/O DUAL FUEL TANK W/ DUAL FUEL TANKS W/O DUAL FUEL TANKS W/ DUAL FUEL TANK WHT (OR WIRE WHT WIRE YEL WIRE YEL/BLK WIRE