GMC Pickup C3500 (1985-2000) tan Wiring diagrams

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 (ON FRONT A/C-HEATER HOUSING) 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 (ON FRONT A/C-HEATER HOUSING) RED WIRE TAN WIRE UNDERHOOD FUSE/RELAY CENTER WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC DOOR SIGNAL 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 AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH 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 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 RECIRCULATION DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD BLOWER FUSE 3 FUSE BLOCK 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 BLOCK VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) 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 RECIRC SIGNAL IGNITION A/C COMP FUSE A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE 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 SIGNAL 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 (ON FRONT A/C-HEATER HOUSING) FRONT TEMPERATURE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER DASH ON TOP OF HEATER-A/C HOUSING) HOT AT ALL TIMES UNDERHOOD FUSE BLOCK HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 IGN E FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (BEHIND RIGHT SIDE OF DASH) PPL REAR DEFOGGER SYSTEM RECIRCULATION DOOR MOTOR (UNDER DASH ON HEATER- A/C HOUSING) RED WIRE TAN WIRE WHT WIRE YEL WIRE

BELT SWITCH BREAKOUT) BLK WIRE CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DOOR LOCK CONTROL MODULE (FRONT OF LEFT REAR WHEELHOUSE) DOOR LOCK RELAY (UNDER CENTER OF DASH) GROUND DOOR JAMB SW LOCK SIG UNLOCK SIG PPL GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK (LEFT SIDE OF DASH, LEFT DOOR LOCK SWITCH LEFT FRONT DOOR JAMB SWITCH LEFT FRONT DOOR LOCK ACTUATOR LEFT REAR DOOR JAMB SWITCH LEFT REAR DOOR LOCK ACTUATOR LOCK LT BLU WIRE ORG/ WIRE PPL PWR ACCY C.B. REAR CARGO DOOR LOCK ACTUATOR (CARGO DOORS) REAR DOOR JAMB SWITCH REAR DOOR LOCK SWITCH (CARGO DOORS) RIGHT DOOR LOCK SWITCH RIGHT FRONT DOOR JAMB SWITCH RIGHT FRONT DOOR LOCK ACTUATOR 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) TAN WIRE UNLOCK W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE

BLK WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF DASH) GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) LEFT FRONT DOOR LOCK MOTOR LEFT FRONT DOOR LOCK SWITCH LOCK LT BLU WIRE ORG/ WIRE PWR-ACCY CIRCUIT BREAKER RIGHT FRONT DOOR LOCK MOTOR RIGHT FRONT DOOR LOCK SWITCH SOLID STATE TAN WIRE UNLOCK 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 HEAD- LAMP RIGHT 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 RUN WIRE TAN WIRE TAN/WHT WIRE UNDERHOOD FUSE BLOCK (LEFT REAR OF ENGINE COMPT) W/ FOG LAMPS 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, BELT SWITCH BREAKOUT) BLK (OR BLK/WHT) WIRE BLK WIRE BLK/WHT WIRE CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DATA LINK CONNECTOR (UNDER LEFT 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, INTERIOR LAMPS SYSTEM LEFT DOOR LOCK SWITCH LEFT FRONT DOOR JAMB SWITCH LEFT FRONT DOOR LOCK ACTUATOR LEFT REAR DOOR JAMB SWITCH LEFT REAR DOOR LOCK ACTUATOR LOCK LT BLU WIRE ORG/ WIRE PNK WIRE PPL PWR-ACCY CIRCUIT BREAKER REAR CARGO DOOR LOCK ACTUATOR (CARGO DOORS) REAR DOOR JAMB SWITCH REAR DOOR LOCK SWITCH (CARGO DOORS) REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT DOOR LOCK SWITCH RIGHT FRONT DOOR JAMB SWITCH RIGHT FRONT DOOR LOCK ACTUATOR 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) TAN WIRE TRUNK, TAIL- GATE, FUEL DOORS SYSTEM UNLOCK UTILITY W/ REAR CARGO DOORS UTILITY W/ REAR LIFT GATE/WINDOW W/ LIFTGATE W/ CARGO DOORS W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE

BATT B BELT SWITCH BREAKOUT) BLK WIRE BLK/WHT WIRE CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) DOOR LOCK RELAY (UNDER CENTER OF DASH, NEAR REMOTE CONTROL DOOR LOCK RECEIVER) DRIVER DR UNLK UNLOCK OUT HORN SIGNAL GAUGES FUSE 4 GROUND GRY WIRE HORNS SYSTEM HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT SIDE OF DASH, INTERIOR LAMPS SYSTEM LEFT DOOR LOCK SWITCH LEFT FRONT DOOR LOCK ACTUATOR LOCK LOCK OUT DOME LAMPS LT BLU WIRE ORG/ WIRE PASS DRS UNLK PNK IGNITION DOME LMP OFF PROGRAM SIG WIRE PNK WIRE PWR ACCY C.B. REMOTE CONTROL DOOR LOCK RECEIVER (UNDER CENTER OF DASH PANEL) RIGHT DOOR LOCK SWITCH RIGHT FRONT DOOR LOCK ACTUATOR SEAT BELT SWITCH BREAKOUT) TAN WIRE UNLOCK W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE