GMC Pickup C3500 (1985-2000) dk blu Wiring diagrams

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID 29 30 VSS LO (GROUND) VSS HI (SIGNAL) ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CRUISE CONTROL DK BLU WIRE ECM 1 FUSE ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE ENGINE CONTROLS ENGINE COOLANT TEMPERATURE SENSOR (TOP RIGHT FRONT OF ENGINE) FLUID TEMP SENSOR FRONT WHEEL LOCK FUEL INJECTORS, IGNITION CONTROL MOUDULE, IGNITION COIL FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GRY WIRE GRY/BLK WIRE HI LO HOT AT ALL TIMES HOT IN HOT IN OFF, RUN OR START HOT IN RUN OR START HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DSAH) GAUGES FUSE 4 I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INLINE GENDER ADAPTOR INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP ORG/ WIRE PNK PNK WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL SOLENOID RED WIRE RED/BLK WIRE REV, LO RUN WIRE TAN WIRE TCC PWM SOLENOID TCC/ABS/ CRUISE SWITCH THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSFER CASE CIRCUIT TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT SIDE OF YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID A/T ISS SENSOR VSS IN SENSOR GROUND SENSOR GROUND APP 1 SIGNAL IN ACCELERATOR PEDAL POSITION MODULE (PART OF ACCELERATOR PEDAL) APP 3 SIGNAL IN SENSOR GROUND A/T ISS SENS LO AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE PPL ENGINE CONTROLS SYSTEM ENGINE SHUTOFF SOLENOID, FUEL SOLENOID EXTERIOR LIGHTS FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HI LO HOT AT ALL TIMES HOT IN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INLINE GENDER ADAPTOR INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP ORG/ WIRE PNK PPL WIRE PNK WIRE POWERTRAIN CONTROL MODULE (RIGHT SIDE OF DASH NEAR BLOWER MOTOR) PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL PNK PNK WIRE PPL PRESS CTRL SOLENOID PPL/WHT WIRE RED WIRE RED/BLK WIRE RUN WIRE STOP/HAZ FUSE 1 TAN WIRE TAN/WHT WIRE TCC PWM SOLENOID TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PNK PNK REV, LO WIRE TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSFER CASE CIRCUIT TRANSFER CASE CIRCUIT PNK WIRE TURN/ HAZARD SWITCH, CHIME MODULE VEHICLE SPEED SENSOR (LEFT SIDE OF VEHICLE SPEED SENSOR BUFFER (RIGHT SIDE OF DASH) WHT WIRE WHT/BLK 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

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID 29 30 VSS LO (GROUND) VSS HI (SIGNAL) ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CRUISE CONTROL DK BLU WIRE ECM 1 FUSE ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE ENGINE CONTROLS ENGINE COOLANT TEMPERATURE SENSOR (TOP RIGHT FRONT OF ENGINE) FLUID TEMP SENSOR FRONT WHEEL LOCK FUEL INJECTORS, IGNITION CONTROL MOUDULE, IGNITION COIL FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GRY WIRE GRY/BLK WIRE HI LO HOT AT ALL TIMES HOT IN HOT IN OFF, RUN OR START HOT IN RUN OR START HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DSAH) GAUGES FUSE 4 I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INLINE GENDER ADAPTOR INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP ORG/ WIRE PNK PNK WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL SOLENOID RED WIRE RED/BLK WIRE REV, LO RUN WIRE TAN WIRE TCC PWM SOLENOID TCC/ABS/ CRUISE SWITCH THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSFER CASE CIRCUIT TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT SIDE OF 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 (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

B+ SHOCK GRD TAMPER BLK WIRE BODY CONTROL MODULE (IN CENTER CONSOLE) CARGO DOOR JAMB SWITCH CTSY FUSE 3 DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DL BLU/WHT WIRE DOOR LOCK DOOR UNLOCK DOOR LOCK INVERSION MODULE (BEHIND LEFT SIDE OF DASH) DOOR UNLOCK DOOR LOCK GRD B+ HEADLIGHT SYSTEM HORNS SYSTEM HOT AT ALL TIMES I/P FUSE BLOCK LEFT FRONT DOOR JAMB SWITCH LEFT REAR DOOR JAMB SWITCH LIFTGATE JAMB SWITCH LT BLU WIRE LT GRN WIRE ORG/ WIRE PPL RIGHT FRONT DOOR JAMB SWITCH RIGHT REAR DOOR JAMB SWITCH SECURITY LED (IN CENTER OF FLOOR CONSOLE) SHOCK SENSOR (IN CENTER CONSOLE) TAN WIRE WHT/BLK WIRE

A/T M/T AIR BAG FUSE 10 BODY CONTROL MODULE BODY REAR CONTROL STEREO MODULE CONTROLLER BRN WIRE CLUTCH PEDAL PARK/NEUTRAL POSITION POSITION SWITCH SWITCH COLUMN HARN BREAKOUT) PNK WIRE CONVENIENCE CENTER CRANK FUSE 8 DAYTIME RUNNING LAMPS MODULE DK BLU WIRE ELECTROCHROMIC REARVIEW MIRROR W/ COMPASS FROM CONVENIENCE CENTER BREAKOUT) FROM IGNITION SWITCH (DIAGRAM 3 OF 6) FROM UNDERHOOD FUSE-RELAY CENTER GAS DIESEL GAUGES FUSE 4 HEADLAMP, PANEL DIMMER SWITCH I/P FUSE BLOCK IGN A FUSE 6 IGN B FUSE 5 IGNITION SWITCH INFLATABLE RESTRAINT I/P MODULE SWITCH (PICKUP) INFLATABLE RESTRAINT SENSING AND DIAGNOSTIC MODULE INTERIOR LAMP CONTROL MODULE OR REMOTE CONTROL DOOR LOCK RECEIVER LOCK OFF M/T M/T A/T ORG/ WIRE OTHERS PNK WIRE POWER WINDOW MASTER SWITCH PPL PWR WDO CIRCUIT BREAKER RADIO RADIO FUSE 17 REAR WINDOW LOCKOUT SWITCH (4-DR) RED WIRE RR WIPER FUSE 23 TRANS FUSE 20 WIPER FUSE 11 RUN WIRE STARTER RELAY TO SEATS FUSE (DIAGRAM 5 OF 6) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 4 OF 6) PNK WIRE TRANSFER CASE SELECT SWITCH TURN B/U FUSE 16 UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL UPPER LEVEL (FLOOR CONSOLE HARN, 33 CM HEATED SEAT SWITCH BREAKOUT) VEHICLE RIGHT FRONT INTERFACE POWER UNIT WINDOW SWITCH (2 DR, UTILITY) VEHICLE SPEED SENSOR BUFFER (DIESEL) W/O RKE W/ RKE WHT WIRE WINDSHIELD WIPER INSTRUMENT MOTOR CLUSTER MODULE YEL WIRE

BATTERY INPUT BLK WIRE BLK/WHT WIRE BODY CONTROL MODULE (IN CENTER CONSOLE) BRN WIRE CTSY FUSE 3 DK BLU WIRE GAUGES FUSE 4 GROUND FASTEN BELTS OUT HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INSTRU- MENT CLUSTER KEY-IN WARNING BUZZER SWITCH LEFT DOOR JAMB SWITCH LT GRN WIRE ORG/ WIRE PKLPS FUSE 9 PNK WIRE POWER DISTRIBUTION SYSTEM SAFETY BELTS INDICATOR SEAT BELT SWITCH (ON DRIVER'S SEAT BELT BUCKLE) SUPPLEMENTAL RESTRAINTS SYSTEM TAN WIRE WHT WIRE YEL WIRE

2-3 SHIFT SOL CTRL 3-2 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 BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK WIRE GRN WIRE IGN FEED SENS RTN INLINE GENDER ADAPTER KNOCK SENS SIG LOW REF FUEL GAUGE LVL TCC SOL CTRL PPL LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE LT LT LT PPL NCA WIRE OTHERS PNK IGNITION FEED WIRE PNK PNK 1 2 3 4 5 6 7 8 WIRE PNK PNK PNK PNK WIRE PNK PPL WIRE PNK WIRE PNK/BLK WIRE PPL PPL PNK WIRE PPL SENSOR RETURN LOW REF VSS SIGNAL CRANK POSIT SENS SIG PPL/WHT WIRE RED/BLK WIRE SENS SIG SENSOR RETURN SENSOR SIGNAL TAN WIRE TAN/BLK 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 WHT WIRE YEL WIRE YEL/BLK WIRE