GMC Pickup C3500 (1985-2000) hi lo 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

BLK WIRE BLU WIRE BRN WIRE BULB CHECK FOG LTS ENABLE CONVENIENCE CENTER DAYTIME RUNNING LAMP INDICATOR INSTRUMENT CLUSTER DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (ENGINE COMPARTMENT FRONT PLENUM PANEL) DIODE DK BLU WIRE DK GRN/WHT WIRE FOG LAMP ON INDICATOR SOLID STATE SWITCH FOG LAMP RELAY FOG LAMP SWITCH GRN WIRE GRY WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT AT ALL TIMES DRL-FOG FUSE 15 HOT IN RUN, BULB TEST OR START FUSE BLOCK GAUGES FUSE 4 ILLUM LAMP LAMP FEED HI BEAM FEED HI BEAM INDICATOR LEFT HIGH BEAM HEADLAMP LEFT LOW BEAM HEADLAMP LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE OUTPUT TO RELAY GROUND PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PICKUP EXT. CAB PNK IGNITION WIRE PNK WIRE PPL PPL LEFT FOG LAMP PPL RIGHT FOG LAMP RIGHT HIGH BEAM HEADLAMP RIGHT LOW BEAM HEADLAMP SUBURBAN PICKUP UTILITY EXT. CAB CREW CAB SUBURBAN UTILITY CREW CAB TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

BLK WIRE BRN WIRE BULB CHECK FOG LTS ENABLE CONVENIENCE CENTER DAYTIME RUNNING LAMP INDICATOR INSTRUMENT CLUSTER DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (ENGINE COMPARTMENT FRONT PLENUM PANEL) DIODE DK BLU WIRE DK GRN/WHT WIRE FOG LAMP ON INDICATOR SOLID STATE SWITCH FOG LAMP RELAY FOG LAMP SWITCH GRN WIRE GRY WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT AT ALL TIMES DRL-FOG FUSE 15 HOT IN RUN, BULB TEST OR START FUSE BLOCK GAUGES FUSE 4 ILLUM LAMP LAMP FEED HI BEAM FEED HI BEAM INDICATOR LEFT HEADLAMP ASSEMBLY HI LO LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE OUTPUT TO RELAY GROUND PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PICKUP EXT. CAB PNK IGNITION WIRE PNK WIRE PPL PPL LEFT FOG LAMP PPL RIGHT FOG LAMP RIGHT HEADLAMP ASSEMBLY HI LO SUBURBAN PICKUP UTILITY EXT. CAB CREW CAB SUBURBAN UTILITY CREW CAB TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

BLK WIRE BRN WIRE FRONT WINDSHIELD WASHER PUMP MOTOR HI LO HI MIST LO OFF INST WIPE PULSE HOT IN ACCY OR RUN I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) MIST OFF INST WIPE NCA WIRE PPL RED WIRE SOLID STATE WASH OFF WASHER SWITCH WINDSHIELD WIPER MOTOR MODULE WINDSHIELD WIPER/ WASHER SWITCH WIPER FUSE 11 WIPER SWITCH YEL WIRE

BLK WIRE BRN WIRE BULB CHECK DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (ENGINE COMPARTMENT FRONT PLENUM PANEL) DK BLU/WHT WIRE DRL FUSE FUSE BLOCK GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN HOT IN RUN, BULB TEST OR START GAUGES FUSE HTR A/C FUSE IGNITION LAMP FEED HI BEAM FEED HI BEAM INDICATOR OUTPUT TO RELAY GROUND INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LT GRN WIRE LT GRN/BLK WIRE LT LT OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PICKUP ONLY PNK/BLK WIRE RIGHT HEADLAMP ASSEMBLY SUBURBAN, UTILITY ONLY TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

BLK WIRE GRN WIRE HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES LEFT HEADLAMP ASSEMBLY LO HI LT GRN WIRE LT INSTRUMENT CLUSTER OFF OFF HEAD HEAD PARK PARK RIGHT HEADLAMP ASSEMBLY TAN WIRE YEL WIRE

BLK WIRE BRN WIRE CONVENIENCE CENTER DK BLU WIRE FOG LAMP ON INDICATOR FOG LAMP RELAY (BEHIND LEFT SIDE OF I/P) FOG LAMP SWITCH SOLID STATE SWITCH FUSE BLOCK GRN WIRE GRY WIRE HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT AT ALL TIMES ACC-BATT CIRCUIT BREAKER ILLUM LAMP LEFT LOW BEAM HEAD- LAMP LT GRN WIRE LT INSTRUMENT CLUSTER LT LT OFF OFF HEAD HEAD PARK ORG/BLK WIRE PARK PNL LPS FUSE PPL PPL PPL RIGHT FOG LAMP LEFT FOG LAMP RIGHT HIGH BEAM HEAD- LAMP LEFT HIGH BEAM HEAD- LAMP RIGHT LOW BEAM HEAD- LAMP TAN WIRE VARIABLE VOLTAGE W/ HEADLIGHT SWITCH IN PARK OR HEAD, RHEOSTAT ADJUSTED WHT WIRE YEL WIRE

BLK WIRE BRN WIRE DK BLU WIRE FOG LAMP ON INDICATOR SOLID STATE SWITCH FOG LAMP RELAY (BEHIND LEFT SIDE OF I/P) FOG LAMP SWITCH GRN WIRE GRY WIRE HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT AT ALL TIMES FUSE BLOCK DRL-FOG FUSE ILLUM LAMP INSTRUMENT CLUSTER LEFT LOW BEAM HEAD- LAMP LT GRN WIRE OFF OFF HEAD HEAD PARK ORG/ WIRE PARK PPL PPL PPL RIGHT FOG LAMP LEFT FOG LAMP RIGHT HIGH BEAM HEAD- LAMP LEFT HIGH BEAM HEAD- LAMP RIGHT LOW BEAM HEAD- LAMP TAN WIRE WHT WIRE YEL WIRE

BLK WIRE BRN WIRE DK BLU WIRE FOG LAMP ON INDICATOR SOLID STATE SWITCH FOG LAMP RELAY (BEHIND LEFT SIDE OF I/P) FOG LAMP SWITCH GRN WIRE GRY WIRE HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT AT ALL TIMES FUSE BLOCK DRL-FOG FUSE ILLUM LAMP INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LO HI LT GRN WIRE OFF OFF HEAD HEAD PARK ORG/ WIRE PARK PPL PPL PPL RIGHT FOG LAMP LEFT FOG LAMP RIGHT HEADLAMP ASSEMBLY TAN WIRE 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