GMC Pickup C2500 (1985-2000) gry Wiring diagrams

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 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

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

AUDIO ALARM MODULE AUXILIARY HEATER/ A/C CONTROL REAR AUXILIARY REAR HEATER/ WIPER/ A/C CONTROL WASHER FRONT SWITCH CARGO LAMP SWITCH CONVENIENCE CENTER CTSY FUSE 3 DAYTIME RUNNING LAMPS RELAY DIODE DK GRN WIRE DRL/FOG FUSE 15 FOG FOG LAMP LAMP RELAY RELAY FOG LAMP SWITCH FROM MAXI FUSE 8 FRONT DOME/ READING LAMPS GLOVE BOX LAMP) GRY WIRE HEADLAMP AND PANEL DIMMER SWITCH I/P FUSE BLOCK ILLUM FUSE 14 INSTRUMENT CLUSTER LEFT FRONT DOOR COURTESY LAMP LEFT I/P SPARE COURTESY POWER LAMP SOURCE LEFT REAR DOOR COURTESY LAMP LEFT VANITY MIRROR ORG/ WIRE PARK LAMPS PICKUP ONLY PICKUP SUBURBAN, UTILITY PK LPS FUSE 9 RADIO HEATER/ CARGO LAMP A/C CONTROL SWITCH LAMP REAR DOME READING LAMPS REAR LIFTGATE RELEASE SWITCH RED WIRE REMOTE OUTSIDE MIRROR SWITCH RIGHT FRONT DOOR COURTESY LAMP RIGHT I/P COURTESY LAMP RIGHT REAR DOOR COURTESY LAMP RIGHT VANITY MIRROR SUBURBAN ONLY SUBURBAN, UTILITY ONLY TWO WHEEL DRIVE INDICATOR

AUDIO ALARM MODULE AUXILIARY HEATER/ A/C CONTROL REAR AUXILIARY REAR HEATER/ WIPER/ A/C CONTROL WASHER FRONT SWITCH CARGO LAMP SWITCH CONVENIENCE CENTER CTSY FUSE 3 DAYTIME RUNNING LAMPS RELAY DIODE DK GRN WIRE DRL/FOG FUSE 15 FOG FOG LAMP LAMP RELAY RELAY FOG LAMP SWITCH FROM MAXI FUSE 8 FRONT DOME/ READING LAMPS GLOVE BOX LAMP) GRY WIRE HEADLAMP AND PANEL DIMMER SWITCH I/P FUSE BLOCK ILLUM FUSE 14 INSTRUMENT CLUSTER LEFT FRONT DOOR COURTESY LAMP LEFT I/P SPARE COURTESY POWER LAMP SOURCE LEFT REAR DOOR COURTESY LAMP LEFT VANITY MIRROR ORG/ WIRE PARK LAMPS PICKUP ONLY PICKUP SUBURBAN, UTILITY PK LPS FUSE 9 RADIO HEATER/ CARGO LAMP A/C CONTROL SWITCH LAMP REAR DOME READING LAMPS REAR LIFTGATE RELEASE SWITCH RED WIRE REMOTE OUTSIDE MIRROR SWITCH RIGHT FRONT DOOR COURTESY LAMP RIGHT I/P COURTESY LAMP RIGHT REAR DOOR COURTESY LAMP RIGHT VANITY MIRROR SUBURBAN ONLY SUBURBAN, UTILITY ONLY TWO WHEEL DRIVE INDICATOR

11 12 PPL A/C SIG AIR CONDITIONING SYSTEM APP 3 SENS SIG FUEL TEMP SIG IAT SIG B/H BARO SENSOR (VIN F) (UPPER LEFT SIDE OF COWL) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE ECM I FUSE EGR CONTROL PRESSURE/ BARO SENSOR (VIN P, S) (UPPER LEFT SIDE OF COWL) ENG-I FUSE FUEL HEATER (TOP REAR OF ENGINE) FUEL PUMP OIL PRESSURE SWITCH FUEL PUMP RELAY (RIGHT UPPER COWL) FUEL PUMP/SENDER (IN FUEL TANK) FUSE BLOCK FUSIBLE LINK FUSIBLE LINKS GAUGES FUSE GLOW PLUG CONTROL RELAY (RIGHT REAR TOP OF ENGINE) GLOW PLUG SIG GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT AT ALL TIMES STOP FUSE HOT IN RUN BRAKE FUSE HOT IN RUN, BULB TEST OR START HOT IN START OR RUN GLOW PLUG FUSE IGNITION FEED 2-3 SHIFT SOL CTRL INSTRUMENT CLUSTER INSTRUMENT CLUSTERS SYSTEM LEFT BANK GLOW PLUGS LT BLU/BLK WIRE LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (TURBO ONLY) (LEFT REAR ENGINE COMPT, AT COWL) ORG/ WIRE ORG/BLK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (UNDER RIGHT END OF I/P) PPL PPL 15 16 RED WIRE RED/BLK WIRE RIGHT BANK GLOW PLUGS SERVICE ENGINE SOON LAMP TAN WIRE TAN/BLK WIRE TCC/ BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) VIN P ONLY WAIT LAMP "SERVICE THROTTLE" LAMP WASTEGATE SOL CTRL EGR VENT SOL CTRL "SERVICE THROTTLE" LAMP WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1222 1224 1225 1226 PNK WIRE 2-3 SHIFT SOL CTRL FUEL INJ CTRL EGR SOL CTRL ENG SHUT-OFF CTRL 4 WHEEL DRIVE LOW SWITCH 983 474 PPL 999 998 961 452 PPL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCELERATOR BRACKET) ANTI-LOCK BRAKES SYSTEM APP 1 SENSOR ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) APP 2 SENSOR APP 3 SENSOR B/H BATTERY FEED FWD LOW SW BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE CRANK FUSE TRANS FUSE CRUISE CONTROL SYSTEM CRUISE ON/OFF SIG DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE SHUT- OFF SOLENOID (TOP FRONT OF ENGINE) FUEL INJ CTRL FUEL SOL FUSE FUEL SOLENOID (TOP FRONT OF ENGINE) FUEL SOLENOID DRIVER (TOP FRONT OF ENGINE) FUSE FUSE BLOCK GRY WIRE GRY/BLK WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN CRANK HOT IN RUN HOT IN START OR RUN LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE OPTICAL SENSOR AND FUEL TEMPER- ATURE SENSOR (TOP FRONT OF ENGINE) ORG/ WIRE ORG/BLK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (UNDER RIGHT END OF I/P) PPL PPL 15 16 PPL/WHT WIRE PRESSURE CONTROL SOL RANGE MODE SELECTOR RED WIRE RED/BLK WIRE RESUME/ACCEL SIG SET/COAST SIG SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) SYSTEM GND CLOSURE SIG APP 2 SENS GND APP 1 SENS GND APP 3 SENS GND SENSOR GND TAN WIRE TAN/WHT WIRE TCC BRAKE SW TCC SOL 2-3 SHIFT SOL 1-2 SHIFT SOL TRANS FLUID TEMP (TFT) SENSOR TRANS INPUT SPD SIG CKP SIG OPTICAL SENS GND OPTICAL SENS CAM SIG TRANS OUTPUT TRANSMISSION INPUT SPEED SENSOR VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VIN P ONLY VSS VSS HI RESOLUTION SIG VSS INPUT VSS OUTPUT WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

A/C SIG AIR CONDITIONING SYSTEM APP 3 SENS SIG FUEL TEMP SIG IAT SIG B/H BARO SENSOR (VIN F) (UPPER LEFT SIDE OF COWL) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE ECM I FUSE EGR CONTROL PRESSURE/ BARO SENSOR (VIN P, S) (UPPER LEFT SIDE OF COWL) ENG-I FUSE FUEL HEATER (TOP REAR OF ENGINE) FUEL PUMP OIL PRESSURE SWITCH FUEL PUMP RELAY (RIGHT UPPER COWL) FUEL PUMP/SENDER (IN FUEL TANK) FUSE BLOCK FUSIBLE LINK FUSIBLE LINKS GAUGES FUSE GLOW PLUG CONTROL RELAY (RIGHT REAR TOP OF ENGINE) GLOW PLUG SIG GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT AT ALL TIMES STOP FUSE HOT IN RUN BRAKE FUSE HOT IN RUN, BULB TEST OR START HOT IN START OR RUN GLOW PLUG FUSE IGNITION FEED INSTRUMENT CLUSTER INSTRUMENT CLUSTERS SYSTEM LEFT BANK GLOW PLUGS LT BLU/BLK WIRE LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (TURBO ONLY) (LEFT REAR ENGINE COMPT, AT COWL) ORG/ WIRE ORG/BLK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (UNDER RIGHT END OF I/P) PPL PPL 15 16 PPL/WHT WIRE RED WIRE RED/BLK WIRE RIGHT BANK GLOW PLUGS SERVICE ENGINE SOON LAMP TAN WIRE TAN/BLK WIRE TCC/ BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) VIN P ONLY WAIT LAMP "SERVICE THROTTLE" LAMP WASTEGATE SOL CTRL EGR VENT SOL CTRL "SERVICE THROTTLE" LAMP WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE