GMC Pickup C2500 (1985-2000) headlamp, panel dimmer switch Wiring diagrams

AUX FUSE 22 AUXILIARY LEAD (TAPED TO HARNESS) BACK-UP LIGHTS CIRCUIT BLK WIRE BLU WIRE BRN WIRE CARGO LAMP CARGO LAMP SWITCH CENTER HIGH MOUNT STOP LAMP CHMSL LAMP (2 BULBS) CRUISE CONTROL SYSTEM CTSY FUSE 3 DK BLU WIRE DK GRN WIRE GRN WIRE GRY WIRE HAZARD NORMAL HEADLAMP, PANEL DIMMER SWITCH HEADLIGHTS SYSTEM HOT AT ALL TIMES HOT AT ALL TIMES UNDER- HOOD FUSE- RELAY CENTER (LEFT REAR OF ENGINE COMPT.) HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK INSTRU- MENT CLUSTER RIGHT TURN INDIC LEFT LEFT FRONT MARKER LAMP LEFT FRONT PARK/ TURN LAMPS LEFT SPOTLAMP ASSEMBLY (POLICE PACKAGE) LEFT TAIL/ STOP/ TURN LAMP DK DK LEFT TURN INDIC LICENSE LICENSE LAMP LAMPS LT BLU WIRE LT GRN WIRE MAXI FUSE 2 NCA WIRE OFF ORG/ WIRE PARK PARK LPS FUSE 9 PICKUP PNK WIRE POLICE PACKAGE (1999 ONLY) PPL REAR CLEARANCE LAMPS CIRCUIT RED WIRE RHEO- STAT RIGHT RIGHT FRONT MARKER LAMP RIGHT FRONT PARK/ TURN LAMPS RIGHT SPOTLAMP ASSEMBLY (POLICE PACKAGE) RIGHT TAIL/ STOP/ TURN LAMP ROOF MARKER LAMPS STOP- LAMP RELAY (EXCEPT SUBUR- BAN/ UTILITY) STOP/ HAZ FUSE 1 STOPLAMP SWITCH (TOP OF BRAKE PEDAL) SUBURBAN/ UTILITY TRAILER TOW CONNECTOR TURN B/U FUSE 16 TURN PWR HAZ PWR FLSHR OUT GND TURN/ HAZARD SWITCH TURN/HAZARD FLASHER (ON CONVENIENCE CENTER) UNDER- HOOD FUSE RELAY CENTER (LEFT REAR OF ENGINE COMPT.) W/ DUAL REAR WHEELS W/ STEP BUMPER W/O STEP BUMPER WHT WIRE YEL 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

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

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

AUDIO ALARM MODULE (ON CONVENIENCE CENTER) AUTOMATIC TRANSFER CASE CONTROL SWITCH (LUXURY) AUTOMATIC TRANSFER CASH SELECT SWITCH AUXILIARY HEATER CONTROL BASE BLK WIRE CARGO LAMP SWITCH (PICKUP ONLY) TRANSFER CASE SWITCH CONVEN- IENCE CENTER DAYTIME RUNNING LAMP (DRL)/ RADIO OVERRIDE SWITCH DAYTIME RUNNING LAMPS (DRL)/ RADIO OVERRIDE SWITCH DISPLAY DIM SIG DISPLAY DISPLAY DIM DIM SIG SIG FOG LAMP SWITCH FRONT AUXILIARY HVAC CONTROL LAMP GRN WIRE GRY WIRE HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HVAC CONTROL LAMP I/P FUSE BLOCK ILLUM FUSE 14 ILLUMINATION INFLATABLE RESTAINT I/P MODULE SWITCH INSTRUMENT CLUSTER LIFTGATE RELEASE SWITCH (SUBUR- BAN/ UTILITIY ONLY) LUXURY OFF ORG/ WIRE PARADE MODE SW PARK PARK LPS FUSE 9 PICKUP/ EXTENDED CAB ONLY PPL PPL PPL RADIO RADIO INFLATABLE RESTAINT I/P MODULE SWITCH REAR AUXILIARY HVAC CONTROL LAMP REAR AUXILIARY HVAC CONTROL SWITCH REAR WINDOW WIPER/ WASHER SWITCH RHEO- STAT SUBURBAN, UTILITY ONLY SWITCH (SUBUR- BAN/ UTILITIY ONLY) TRANSFER CASE SHIFT ILLUMINATION LAMP TRANSFER CASE SWITCH WHT WIRE

ASH TRAY LAMP BLK WIRE BODY CONTROL MODULE (IN CENTER CONSOLE) BRN WIRE GARAGE DOOR OPENER LAMP HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES I/P FUSE BLOCK LEFT FRONT POWER WINDOW SWITCH LEFT REAR HEATED SEAT SWITCH LEFT REAR POWER WINDOW SWITCH OFF ORG/ WIRE PARADE MODE SW PARK PARK LPS FUSE 9 POWER OUTSIDE REARVIEW MIRROR SWITCH REAR STEREO CONTROLLER REAR WINDOW LOCKOUT SWITCH RHEO- STAT RIGHT FRONT POWER WINDOW SWITCH RIGHT REAR HEATED SEAT SWITCH RIGHT REAR POWER WINDOW SWITCH

A/T M/T AIR BAG FUSE 10 BODY CONTROL MODULE BODY REAR RADIO 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 5) FROM UNDERHOOD FUSE BLOCK 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, DIAGNOSTIC MODULE INTERIOR LAMP CONTROL MODULE OR REMOTE CONTROL DOOR LOCK RECEIVER LOCK OFF LUXURY LUXURY ONLY M/T M/T A/T ORG/ WIRE OTHERS PNK WIRE POWER WINDOW MASTER SWITCH PPL PWR WDO CIRCUIT BREAKER RADIO BATT 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 UNDERHOOD FUSE BLOCK (DIAGRAM 4 OF 5) PNK WIRE TO UNDERHOOD FUSE BLOCK (DIAGRAM 5 OF 5) TRANSFER CASE SELECT SWITCH TURN B/U FUSE 16 UNDERHOOD FUSE BLOCK 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

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

BLK WIRE BLU WIRE BRN WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF DASH) DK BLU WIRE DK GRN WIRE DK PPL DOWN HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HOT IN RUN I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) LEFT FRONT LEFT FRONT POWER WINDOW MASTER SWITCH LEFT FRONT WINDOW MOTOR LEFT REAR LEFT REAR WINDOW MOTOR LEFT REAR WINDOW SWITCH LT BLU WIRE LT GRN WIRE ORG/ WIRE PK LPS FUSE PPL PWR WDO CIRCUIT BREAKER RIGHT FRONT RIGHT FRONT WINDOW MOTOR RIGHT FRONT WINDOW SWITCH RIGHT REAR RIGHT REAR WINDOW MOTOR RIGHT REAR WINDOW SWITCH SOLID STATE TAN WIRE UP DOWN WINDOW LOCKOUT SWITCH YEL WIRE

BLK WIRE BRN WIRE END- GATE MARK- ER LAMPS ENDGATE CROUND EXTERIOR LAMPS CIRCUIT HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES I/P FUSE BLOCK LEFT FRONT CLEAR- ANCE LAMP LEFT REAR CLEAR- ANCE LAMP LEFT REAR FENDER LEFT TAIL/ STOP/ TURN LAMP OFF ORG/ WIRE PARADE MODE SW PARK PARK LPS FUSE 9 RHEO- STAT RIGHT FRONT CLEAR- ANCE LAMP RIGHT REAR CLEAR- ANCE LAMP RIGHT REAR FENDER RIGHT TAIL/ STOP/ TURN LAMP