GMC Forward Control P3500 (1985-1999) headlamp dimmer switch Wiring diagrams

** (RIGHT FRAME RAIL, NEAR BATTERY) A/C COMPRESSOR CLUTCH AUXILLIARY COOLING FAN AUDIO ALARM MODULE AUTO APPLY PARK BRAKE DATA LINK CONN- ECTOR POWERTRAIN CONTROL MODULE (PCM) AUXILLIARY COOLING FAN COOLANT PRESSURE SWITCH BATTERY BLK WIRE BLK/WHT WIRE BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID BRAKE/ TRANSMISSION SHIFT INTERLOCK RELAY CRUISE CONTROL MODULE DAYTIME RUNNING LAMPS MODULE DAYTIME RUNNING LAMPS RELAY FUEL PUMP FUEL PUMP RELAY G# N/A (AT LEFT REAR FRAME RAIL) G# N/A (AT LEFT SHIPPING PANEL) G#S N/A (IN FORWARD LAMPS HARNESS) HEADLAMP DIMMER SWITCH I/P CLUSTER LEFT HIGH BEAM HEADLAMP LEFT HIGH/LOW BEAM HEADLAMP PROVISIONS FOR LEFT SIDE MARKER LAMP PROVISIONS FOR RIGHT SIDE MARKER LAMP RIGHT HIGH BEAM HEADLAMP RIGHT HIGH/LOW BEAM HEADLAMP TAN WIRE TRANSMISSION RANGE INDICATOR LAMP VEHICLE SPEED SENSOR BUFFER W/ DAYTIME RUNNING LIGHTS WHT/ BLK WIRE WIPER/ WASHER SWITCH

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

BLK WIRE BRN WIRE DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (IN I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (IN I/P HARNESS) DK BLU/WHT WIRE DK GRN/YEL WIRE FUSE BLOCK GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HORN/DM FUSE HOT AT ALL TIMES HOT IN RUN HTR FUSE INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PROVISIONS FOR FOG LAMPS RIGHT HEADLAMP ASSEMBLY TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

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

BLK WIRE DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) DK BLU/WHT WIRE DRL FUSE FUSE BLOCK GAUGES FUSE GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START IGNITION LAMP FEED HI BEAM FEED HI BEAM INDICATOR OUTPUT TO RELAY GROUND INSTRUMENT CLUSTER LEFT HIGH BEAM HEADLAMP LEFT LOW BEAM HEADLAMP LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (ON PARK BRAKE SUPPORT BRACKET) PNK/BLK WIRE PPL PPL BULB CHECK RIGHT HIGH BEAM HEADLAMP RIGHT LOW BEAM HEADLAMP TAN WIRE WHT WIRE YEL WIRE

BLK WIRE GRN WIRE HEADLAMP DIMMER SWITCH HI BEAM INDICATOR HI LO HOT AT ALL TIMES INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY HI LEFT LOWER HEAD- LAMP (W/ HPR) LIGHT SWITCH LT GRN WIRE OFF OFF HEAD HEAD PARK PARK RIGHT HEADLAMP ASSEMBLY LO HI RIGHT LOWER HEAD- LAMP (W/ HPR) TAN WIRE YEL WIRE

BLK WIRE BLU WIRE BRN WIRE DAYTIME RUNNING LAMP CUTOFF RELAY DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (IN I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (IN I/P HARNESS) DK BLU/WHT WIRE DK GRN/YEL WIRE GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HORN/DM FUSE HOT AT ALL TIMES HOT IN RUN OR START FUSE BLOCK HTR FUSE INSTRUMENT CLUSTER LEFT HEADLAMP ASSEMBLY LEFT LOWER HEADLAMP (W/ HPR) LT GRN WIRE LT GRN/BLK WIRE OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (AT PARK BRAKE, UNDER LEFT SIDE OF I/P) PROVISIONS FOR FOG LAMPS RIGHT HEADLAMP ASSEMBLY RIGHT LOWER HEADLAMP (W/ HPR) TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE

BLK WIRE DAYTIME RUNNING LAMPS CONTROL MODULE (ATTACHED TO I/P HARNESS) DAYTIME RUNNING LAMPS RELAY (LEFT SIDE OF DASH, ON RELAY BRACKET) DIODE NETWORK (ON I/P HARNESS) DK BLU WIRE DK GRN/WHT WIRE DRL INDICATOR FUSE BLOCK BREAKOUT) FUSIBLE LINK (16 GA- GAUGES FUSE 8 GRN WIRE HEADLAMP DIMMER SWITCH HEADLAMPS SWITCH OFF HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK IGNITION SWITCH INSTRUMENT CLUSTER LEFT HEAD- LAMP LO HI LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE LT LT ORG/ WIRE PARK BRAKE IN FOG LAMPS PARK BRAKE INDICATOR SWITCH (ON PARK BRAKE LEVER) PARK HEAD PNK IGNITION LAMP FEED HI BM INPUT HI BM INDICATOR RELAY CONTROL GROUND WIRE PNK WIRE RED WIRE RIGHT HEAD- LAMP RUN WIRE TAN WIRE WHT WIRE YEL WIRE

BLK WIRE DAYTIME RUNNING LAMP INDICATOR DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF I/P) DAYTIME RUNNING LAMPS RELAY (BEHIND LEFT SIDE OF I/P, ABOVE STEERING COLUMN) DK BLU/WHT WIRE DRL FUSE FUSE BLOCK GAUGES FUSE GRN WIRE HEAD PARK HEADLAMP DIMMER SWITCH HEADLIGHT SWITCH ASSEMBLY HI BEAM INDICATOR HI LO HOT AT ALL TIMES HOT IN RUN OR START IGNITION LAMP FEED HI BEAM FEED HI BEAM INDICATOR OUTPUT TO RELAY GROUND INSTRUMENT CLUSTER LEFT HIGH BEAM HEADLAMP LEFT LOW BEAM HEADLAMP LT GRN WIRE LT GRN/BLK WIRE LT LT OFF OFF HEAD ORG/ WIRE PARK PARK BRAKE WARNING SWITCH (ON PARK BRAKE SUPPORT BRACKET) PNK/BLK WIRE PPL PPL BULB CHECK RIGHT HIGH BEAM HEADLAMP RIGHT LOW BEAM HEADLAMP TAN WIRE WHT WIRE YEL WIRE

1995 VFTC BLK WIRE GRN WIRE HEADLAMP DIMMER SWITCH HI BEAM INDICATOR HI LO HOT AT ALL TIMES LEFT HIGH BEAM HEADLAMP ASSEMBLY LEFT LOW BEAM HEADLAMP ASSEMBLY LIGHT SWITCH LT GRN WIRE LT INSTRUMENT CLUSTER OFF OFF HEAD HEAD PARK PARK RIGHT HIGH BEAM HEADLAMP ASSEMBLY RIGHT LOW BEAM HEADLAMP ASSEMBLY TAN WIRE YEL WIRE