Chevrolet Pickup K2500 (1988-2000) hot in run or start 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

A/T M/T ACCY ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRAKE PRESSURE WARNING SWITCH (ON REAR OF EBCM CASTING) BRN WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DUAL FUEL TANKS SINGLE FUEL TANK ELECTRONIC BRAKE CONTROL MODULE (EBCM) (ON LEFT SIDE OF ENGINE COMPT) ENG-1 MINI FUSE ENGINE CONTROLS SYSTEM (FUEL PUMP BALANCE RELAY) ENGINE CONTROLS SYSTEM RADIO ENGINE CONTROLS SYSTEM FUEL GAUGE SENDER (IN FRONT FUEL TANK) FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE OF FRAME RAIL) FUEL PUMP/ SENDER GAUGES FUSE 4 GRN WIRE HOT IN RUN OR START HOT IN RUN OR START FUSE/RELAY BLOCK (LEFT REAR OF ENGINE COMPT) HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) IGN E MINI FUSE IGN SW BRAKE IND BRAKE PSI PK BRAKE 33 33 IGNITION SWITCH LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE PARK BRAKE SWITCH (ON PARK BRAKE PEDAL BRACKET) PNK 639 975 970 497 451 30 WIRE PNK PNK WIRE PNK PPL WIRE PNK WIRE PPL PPL/WHT WIRE RUN WIRE SECONDARY FUEL GAUGE SENDER (IN REAR FUEL TANK) TAN/WHT WIRE TRANS FUSE 20 TWISTED PAIR VEHICLE SPEED SENSOR (LEFT SIDE OF TRANSMISSION, LEFT SIDE OF TRANSFER CASE VEHICLE SPEED SENSOR (VSS) ADAPTER VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF DASH) YEL/BLK WIRE

BACKUP LAMPS SIGNAL (TRAILER TOW PACKAGE) (WIRE CUT AND TAPED TO HARNESS) BLK WIRE FROM LICENSE LAMP BREAKOUT) HOT IN RUN OR START I/P FUSE BLOCK LEFT BACKUP LAMP LT GRN WIRE MIRRORS SYSTEM PARK/NEUTRAL POSITION SWITCH (LEFT CENTER OF TRANSMISSION) PNK A/T WIRE PNK M/T WIRE PNK WIRE RIGHT BACKUP LAMP TURN B/U FUSE 16

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

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 5 CM FROM TRANSFER CASE RELAY BREAKOUT FROM AXLE SWITCH) 79 CM FROM ENGINE HARNESS BREAK-OUT) 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 FRONT AXLE ACTUATOR FRONT AXLE SWITCH FRONT AXLE SWITCH (RIGHT REAR OF FRONT DRIVE AXLE) FUSE 24 GASOLINE GAUGES FUSE 4 GROUND GROUND GROUND BATTERY IN BATTERY IN PNP SWITCH OUT 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) ILLUMINATION LAMP LT BLU WIRE LT GRN WIRE ORG (OR LT GRN/BLK) WIRE ORG/ WIRE PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK IGNITION IN ENCODER GROUND GROUND 2 HI INDIC CTRL 4 HI INDIC CTRL WIRE PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) PPL/WHT WIRE REAR LIFTGATE WINDOW RELEASE CIRCUIT RED WIRE RED/WHT WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY SPARE POWER SOURCE TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANS- MISSION CIRCUIT TRANSFER CASE CONTROL MODULE (STEERING COLUMN BRACKET) TRANSFER CASE ENCODER (LEFT SIDE CENTER OF TRANSFER CASE) TRANSFER CASE ENCODER MOTOR (LEFT SIDE OF TRANSFER CASE) TRANSFER CASE RELAY (1-TON VEHICLES ONLY) (RIGHT SIDE OF FIREWALL) TRANSFER CASE SELECT SWITCH TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) TURN B/U FUSE 16 TURN SIGNAL SWITCH WHT WIRE YEL WIRE YEL/BLK WIRE