GMC Pickup C1500 (1985-1999) yel Wiring diagrams

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL 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 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 FUSE 3 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 MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE GRY/BLK WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER 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-RELAY CENTER VALVE CTRL AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) WATER VALVE (SUBURBAN, UTILITY, CREW CAB ONLY) (RIGHT CENTER OF INTAKE AREA) WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMP FUSE 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 ENABLE A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) AIR TEMP DR SENSOR 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 (UNDER DASH ON HEATER- A/C CASE) FUSE BLOCK GRY WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER DASH ON TOP OF HEATER-A/C CASE) HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 IGN 1 FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (LEFT REAR OF ENGINE COMPT) PPL REAR DEFOGGER SYSTEM RED WIRE TAN WIRE WHT WIRE YEL WIRE

BLK WIRE BLK/WHT WIRE BRN WIRE DATA LINK CONNECTOR (DLC) (LEFT SIDE OF DASH) DK GRN WIRE ELECTRONIC POWER STEERING SYSTEM ENGINE CONTROLS SYSTEM EVO SOL FEED EVO SOL OUT EVO/PASSLOCK MODULE (NEAR DASH AUXILIARY STORAGE COMPARTMENT) GAUGES FUSE 4 GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK INSTRUMENT CLUSTER LT BLU WIRE NCA WIRE ORG/ WIRE ORG/BLK WIRE PASSLOCK SENSOR (IN STEERING COLUMN, NEAR LOCK CYLINDER) PNK PPL WIRE PNK WIRE PPL RED WIRE RED/WHT WIRE RESISTOR 10 OHMS SEC/STRG FUSE 21 SECURITY INDICATOR SENSOR PASSLOCK GRD SIGNAL STEERING HANDWHEEL SPEED SENSOR (SENSOR GROUND) 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 LAMPS MODULE (BEHIND LEFT SIDE OF DASH) DAYTIME RUNNING LAMPS RELAY DIODE 203 DRL INDICATOR DRL-FOG FUSE 15 FOG LAMP RELAY FOG LAMP SWITCH GAGES FUSE 4 GRN WIRE GROUND GRY WIRE HEAD OFF PARK HEAD- LAMP DIMMER SWITCH HEADLAMP AND 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 PARK LAMP BREAKOUT) PPL PK LPS FUSE 9 PNK WIRE PPL RED WIRE RIGHT FOG LAMP RUN WIRE TAN WIRE TAN/WHT WIRE UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) W/ FOG LAMPS W/ HARN BREAKOUT) FOG LAMPS WHT WIRE YEL 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 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 RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL 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 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 RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL 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 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 RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL WIRE

7.4L A/C COMP FUSE A/C COMPRESSOR CLUTCH RELAY ABS FUSE 4 AUX FAN FUSE AUXILIARY COOLING FAN RELAY AUXILIARY HIGH BLOWER MOTOR RELAY BLK WIRE BLOWER FUSE 3 BLU WIRE BRAKE CONTROL MODULE BREAKOUT) BRAKE LAMP RELAY UNDERHOOD FUSE-RELAY CENTER HEADLAMP AND PANEL DIMMER SWITCH CAMP/TRAIL FUSE CARGO LAMP SWITCH CONVENIENCE CENTER CONVENIENCE CENTER EVO/ PASSLOCK MODULE CTSY FUSE 3 RADIO BATT FUSE 19 DAYTIME RUNNING LAMPS RELAY DIESEL GASOLINE DIODE DRL/FOG FUSE 15 DUAL BATTERY ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE FOG LAMP RELAY FRONT DOME/ READING LAMPS FUEL PUMP OIL PRESSURE SWITCH AND SENDER FUEL PUMP RELAY UNDERHOOD FUSE-RELAY CENTER FUSIBLE LINK (10 GA-RUST) GAS ONLY GENERATOR (BASE) GENERATOR (UPLEVEL) HEADLAMP AND PANEL DIMMER SWITCH INSTRUMENT CLUSTER (POLICE PACKAGE) HEATER AND A/C CONTROL SWITCH HORN FUSE HORN UNDERHOOD RELAY REEL LAMP UNDERHOOD FUSE- (GAS RELAY CENTER ONLY) I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK INFLATABLE RESTRAINT SWITCH BREAKOUT) INTERIOR LAMP CONTROL MODULE LEFT BATTERY (DIESEL) LEFT RIGHT ILLUMINATED ILLUMINATED VANITY VANITY MIRROR MIRROR MEGA FUSE BLOCK NCA WIRE ORG/ WIRE PICKUP ONLY PK LPS FUSE 9 AUX FUSE 22 POLICE PACKAGE ONLY POWERTRAIN CONTROL MODULE (DIESEL) REAR HOMELINK OVERHEAD DOME/ TRANSMITTER CONSOLE READING READING LAMPS LAMPS RED WIRE REMOTE BATTERY STUD RIGHT BATTERY RIGHT FRONT DOOR COURTESY LAMP RIGHT LEFT COURTESY COURTESY LAMP LAMP ROOF CLEARANCE LAMP SWITCH RR DEFOG FUSE SECURITY/STRG FUSE 21 SEO FUSE SINGLE BATTERY (BASE) SINGLE BATTERY (UPLEVEL) SPARE POWER SOURCE SPOTLAMP SPOTLAMP CONVENIENCE (POLICE (POLICE RADIO CENTER PACKAGE) PACKAGE) STARTER MOTOR SOLENOID STOP FUSE 2 LIGHTING FUSE 8 TO FUSIBLE LINK (DIAGRAM 4 OF 5) TO MEGAFUSE (DIAGRAM 5 OF 5) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 2 OF 5) UNDERHOOD FUSE-RELAY CENTER UNDERHOOD LAMP VEHICLE CONTROL MODULE (GASOLINE) YEL WIRE

A/T AUDIO ALARM MODULE AUTOMATIC AUTOMATIC TRANSFER CASE AUTOMATIC TRANSFER CASE CONTROL MODULE AUX/PWR FUSE 7 AUXILIARY POWER CONNECTOR BLK WIRE BRN WIRE CIG LTR FUSE 13 CIGAR LIGHTER CLUTCH PEDAL POSITION SWITCH COLUMN HARNESS BREAKOUT) CONVENIENCE CENTER CRANK FUSE 8 TRANS FUSE 20 DATA LINK CONNECTOR DOOR LOCK CONTROL MODULE (W/ CARGO DOORS) DOOR RIGHT FRONT LOCK DOOR LOCK RELAY SWITCH ELECTRIC FROM CONVENIENCE CENTER BREAKOUT) FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 1 OF 5) I/P CLUSTER BREAKOUT) I/P FUSE BLOCK IGN A FUSE 6 IGN B FUSE 5 IGNITION SWITCH INSTRUMENT CLUSTER LAMP BREAKOUT) LEFT FRONT RIGHT FRONT DOOR LOCK DOOR LOCK SWITCH SWITCH LEFT POWER LEFT FRONT SEAT DOOR LOCK ADJUSTER SWITCH SWITCH LIFTGATE RELEASE SWITCH LOCK LOCK OFF LOCK OFF OFF M/T MAXI FUSE 7 NCA WIRE ORG/ WIRE PARK/NEUTRAL TRANS- POSITION MISSION SWITCH CONTROLS PICKUP PNK WIRE POWER AMPLIFIER RELAY (SUBURBAN) POWER OUTLET BREAKOUT) POWER REAR WINDOW WINDOW MASTER LOCKOUT SWITCH SWITCH (4-DR) POWER WDO CIRCUIT BREAKER PPL PWR-ACCY CIRCUIT BREAKER RADIO FUSE 17 RADIO RIGHT FRONT POWER WINDOW SWITCH (2 DR, UTILITY) REAR DOOR LOCK SWITCH RED WIRE REMOTE CONTROL DOOR LOCK POWER RECEIVER SEAT LUMBAR SWITCH REMOTE CONTROL DOOR LOCK RECEIVER RIGHT LUMBAR POWER SEAT SWITCH RIGHT POWER SEAT ADJUSTER SWITCH RR WIPER FUSE 23 WIPER FUSE 11 RUN WIRE STARTER RELAY UNDERHOOD FUSE-RELAY CENTER STEERING COLUMN HARNESS BREAKOUT) STOP LAMP SWITCH STOP/HAZ FUSE 1 SUBURBAN ONLY SUBURBAN/ UTILITY T CASE FUSE 2 TO SEATS FUSE (DIAGRAM 4 OF 5) TRANSFER CASE CONTROL MODULE TURN/ HAZARD SWITCH UNDERHOOD FUSE-RELAY CENTER W/BENCH SEAT RIGHT FRONT POWER LUMBAR SEAT SWITCH WHT WIRE WINDSHIELD WIPER MOTOR MODULE YEL WIRE

4.3L PNK WIRE 6.5L 7.4L W/ CALIFORNIA EMISSIONS OTHERS A/C CLUTCH RELAY A/C COMPRESSOR CLUTCH RELAY A/T M/T AIR BAG FUSE 10 AIR RELAY BACKUP LAMP SWITCH BREAKOUT) COLUMN HARNESS BREAKOUT) PNK WIRE CONVENIENCE CENTER CRANK- FUEL SHAFT INJECTOR POSITION SENSOR DAYTIME AUDIO RUNNING ALARM LAMPS MODULE RELAY ECM-1 MINI FUSE EGR FUEL GLOW EGR LINEAR HEATER PLUG BOOST PWM VALVE RELAY SOLENOID SOLENOID ELECTRIC SHIFT ELECTROCHROMATIC REARVIEW MIRROR W/ COMPASS ENG-1 MINI FUSE ENGINE SHUTOFF SOLENOID EVAPORATIVE EMISSION CANISTER VENT EVO/ PASSLOCK MODULE FROM EBCM BREAKOUT) FROM IGNITION SWITCH (DIAGRAM 2 OF 5) FROM STEERING COLUMN HARNESS BREAKOUT) FUEL FUEL FUEL INJECTOR INJECTOR INJECTOR FUEL FUEL INJECTOR INJECTOR FUEL INJECTOR FUEL INJECTOR BREAKOUT) FUEL SOLENOID DRIVER FUEL TANK DAYTIME SENDER RUNNING INSTRUMENT MODULE LAMPS CLUSTER MODULE (4.3L) GASOLINE DIESEL 5.0L, 5.7L 4.3L 7.4L GAUGES FUSE 4 HEATED HEATED OXYGEN OXYGEN SENSOR SENSOR BANK 1 BANK 1 SENSOR 3 SENSOR 2 I/P FUSE BLOCK IGN E MINI FUSE IGNITION CONTROL MODULE INFLATABLE RESTRAINT I/P MODULE SWITCH INFLATABLE RESTRAINT SENSING AND DIAGNOSTIC MODULE M/T MASS AIR FLOW SENSOR PARK/ NEUTRAL POSITION SWITCH PNK FUEL INJECTOR BREAKOUT) WIRE PNK WIRE POWERTRAIN CONTROL MODULE TURN B/U FUSE 16 TURN SIGNAL SWITCH UNDERHOOD FUSE-RELAY CENTER VEHICLE IGNITION CONTROL COIL MODULE WATER-IN- EGR FUEL SOLENOID SENSOR YEL WIRE