Chevrolet Cab & Chassis C3500 (1989-2000) hot at all times 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 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 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

BLK WIRE CARGO DOOR JAMB SWITCH (EXCEPT CREW CAB) COURTESY LAMPS CTRL CTSY FUSE 3 DOME DEFEAT DOOR JAMB FRONT DOME/ READING LAMPS GRY WIRE HEADLAMP, PANEL DIMMER SWITCH DOME LAMP DEFEAT HORN FUSE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK GAGES FUSE 4 I/P COMPART- MENT BOX LAMP I/P FUSE BLOCK IGN SW INTERIOR LAMP CONTROL MODULE (UNDER CENTER OF DASH) LAMP OUT LEFT FRONT DOOR COURTESY LAMP LEFT FRONT DOOR JAMB SWITCH LEFT I/P COURTESY LAMP LEFT ILLUMINATED VANITY MIRROR LEFT REAR DOOR COURTESY LAMP LEFT REAR DOOR JAMB SWITCH MIRRORS SYSTEM NCA WIRE ORG/ WIRE OVERHEAD CONSOLE LAMPS CIRCUIT PNK PNK WIRE PNK WIRE PPL REAR DOME READING LAMPS REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR COURTESY LAMP RIGHT FRONT DOOR JAMB SWITCH RIGHT I/P COURTESY LAMP RIGHT ILLUMINATED VANITY MIRROR RIGHT REAR DOOR COURTESY LAMP RIGHT REAR DOOR JAMB SWITCH UNDERHOOD FUSE-RELAY CENTER UNDERHOOD REEL LAMP W/ OVERHEAD CONSOLE W/ RKE W/O OVERHEAD CONSOLE W/O RKE W/O RKE W/ RKE WHT WIRE

4-DOOR TRUCKS ONLY BLK WIRE CARGO DOOR JAMB SWITCH (SUBURBAN, TAHOE, YUKON) CTRL CTSY FUSE 3 DOME DEFEAT DOOR JAMB FRONT DOME AND READING LAMP GAGES FUSE 4 GRY WIRE HEADLAMP AND PANEL DIMMER SWITCH DOME LAMP DEFEAT COURTESY LAMPS HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK IGN SW INTERIOR LAMP CONTROL MODULE (UNDER CENTER OF DASH) LAMP OUT LEFT FRONT DOOR JAMB SWITCH LEFT I/P COURTESY LAMP LEFT ILLUMINATED VANITY MIRROR LEFT REAR DOOR JAMB SWITCH MIRRORS SYSTEM NCA WIRE ORG/ WIRE PNK WIRE PPL REAR DOME AND READING LAMP REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR JAMB SWITCH RIGHT I/P COURTESY LAMP RIGHT ILLUMINATED VANITY MIRROR RIGHT REAR DOOR JAMB SWITCH UNDERHOOD FUSE-RELAY CENTER HORN FUSE UNDERHOOD LAMP PPL UNDERHOOD REEL LAMP W/ RKE W/O RKE WHT WIRE

BLK WIRE CARGO LAMP CTRL CTSY FUSE 3 DOME DEFEAT DOME DEFEAT IGN SW DOOR JAMB FRONT DOME AND READING LAMP GRY WIRE HEADLAMP AND PANEL DIMMER SWITCH DOME LAMP DEFEAT COURTESY LAMPS HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK I/P FUSE BLOCK GAGES FUSE 4 IGN SW INTERIOR LAMP CONTROL MODULE (UNDER CENTER OF DASH) LAMP OUT LEFT I/P COURTESY LAMP LEFT ILLUMINATED VANITY MIRROR MIRRORS SYSTEM NCA WIRE ORG/ WIRE PNK WIRE PPL (NOT USED) PPL PPL REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR JAMB SWITCH LEFT FRONT DOOR JAMB SWITCH RIGHT I/P COURTESY LAMP RIGHT ILLUMINATED VANITY MIRROR UNDERHOOD FUSE-RELAY CENTER HORN FUSE UNDERHOOD LAMP UNDERHOOD REEL LAMP W/ RKE W/O RKE WHT WIRE

1134 1134 39 10 10 PARK BRAKE SIG IND BULB CHK IGNITION LAMP FEED PNK WIRE 33 33 BRAKE IND CTRL BRAKE WARN IN 592 592 150 DRL RELAY CTRL BLK WIRE BLK/WHT WIRE BRN WIRE BULB TEST CONVENIENCE CENTER (UNDER LEFT SIDE OF DASH) DAYTIME RUNNING LAMP MODULE (BEHIND LEFT SIDE OF DASH) DAYTIME RUNNING LAMPS RELAY DIODE 203 DRL INDICATOR DRL-FOG FUSE 15 FOG LAMP RELAY FOG LAMP SWITCH GAUGES FUSE 4 GRN WIRE GROUND GRY WIRE HEAD OFF PARK HEAD- LAMP DIMMER SWITCH HEADLAMP, PANEL DIMMER SWITCH HIGH BEAM INDICATOR HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT SIDE OF DASH, IGNITION SWITCH ILLUM LAMP INSTRUMENT CLUSTER INSTRUMENT CLUSTER SYSTEM (BRAKE WARNING INDICATOR) LEFT FOG LAMP LEFT LOW BEAM HEAD- LAMP LEFT HIGH BEAM HEAD- LAMP RIGHT HIGH BEAM HEAD- LAMP LIGHTING FUSE 8 LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE OFF ON INDICATOR ORG/ WIRE PARK BRAKE WARNING SWITCH PK LPS FUSE 9 PNK WIRE PPL RED WIRE RIGHT FOG LAMP RIGHT LOW BEAM HEAD- LAMP RUN WIRE TAN WIRE TAN/WHT WIRE UNDERHOOD FUSE BLOCK (LEFT REAR OF ENGINE COMPT) W/ FOG LAMPS WHT WIRE YEL WIRE

33 (OR 1134) 592 592 150 DRL RELAY CTRL BLK WIRE BLK/WHT WIRE BRN WIRE BULB CHECK 1317 39 10 10 FOG LAMPS IGNITION LAMP FEED PNK WIRE DIODE 203 (I/P HARNESS, RIGHT SIDE OF STEERING COLUMN) DK BLU WIRE DK GRN/WHT WIRE DRL-FOG FUSE 15 FOG LAMP RELAY (UNDER LEFT END OF I/P) FOG LAMP SWITCH GAGES FUSE 4 GRN WIRE GROUND GRY WIRE HEAD HEAD OFF OFF PARK PARK HEAD- LAMP DIMMER SWITCH HEADLAMP, PANEL DIMMER SWITCH HI LO HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK IGNITION SWITCH ILLUM LAMP INSTRUMENT CLUSTER HI BEAM INDI- CATOR DRL INDI- CATOR INSTRUMENT CLUSTER SYSTEM LEFT FOG LAMP RIGHT FOG LAMP LEFT HEAD- LAMP LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE OFF ON INDICATOR ORG/ WIRE PARK BRAKE WARNING SWITCH (ON PARK BRAKE) PNK WIRE PPL PPL PPL RIGHT HEAD- LAMP TAN WIRE TAN/WHT WIRE W/ FOG LAMPS 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