GMC Pickup C1500 (1985-1999) yel Wiring diagrams

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 (ON FRONT A/C-HEATER HOUSING) 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 (ON FRONT A/C-HEATER HOUSING) RED WIRE TAN WIRE UNDERHOOD FUSE/RELAY CENTER WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC DOOR SIGNAL 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 AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH 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 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 RECIRCULATION DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD BLOWER FUSE 3 FUSE BLOCK 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 BLOCK VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) 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 (ON FRONT A/C-HEATER HOUSING) 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 (ON FRONT A/C-HEATER HOUSING) RED WIRE TAN WIRE UNDERHOOD FUSE/RELAY CENTER WHT WIRE YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC DOOR SIGNAL 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 AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH 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 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 RECIRCULATION DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD BLOWER FUSE 3 FUSE BLOCK 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 BLOCK VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) WHT WIRE YEL WIRE

BLK WIRE BRN WIRE CONVENIENCE CENTER FRONT HEATED SEATS FUSE HEATED SEAT SW SIG HIGH/LOW SIG HOT AT ALL TIME HOT IN RUN RR HVAC FUSE 5 I/P FUSE BLOCK INDICATOR LMP FEED LEFT HEATED SEAT MODULE (UNDER LEFT POWER SEAT) LEFT HEATED SEAT SWITCH LT BLU WIRE LT BLU/BLK WIRE OFF OFF LO ORG/ WIRE PNK/BLK WIRE POWER SEAT CIRCUIT PPL RIGHT HEATED SEAT MODULE (UNDER RIGHT POWER SEAT) RIGHT HEATED SEAT SWITCH SEAT BELT SWITCH (ON DRIVER SEAT BELT BUCKLE) SEAT CUSHION ELEMENT SIG ENABLE THERMISTOR UNDERHOOD FUSE/RELAY CENTER YEL WIRE

BLK/WHT WIRE BRN WIRE CAPACITOR DK GRN/WHT WIRE ELECTRONIC POWER STEERING SYSTEM ENGINE CONTROLS SYSTEM EVO SOL FD EVO SOL OUT EVO/PASSLOCK MODULE (UNDER CENTER OF DASH) 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 (INTERNAL TO STEERING COLUMN) PASSLOCK SIGNAL PNK PPL WIRE PNK WIRE PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) RED WIRE RED/WHT WIRE RESISTOR 10 OHMS SECURITY FUSE 21 SECURITY INDICATOR SENSOR GRD STEERING HANDWHEEL SPEED SENSOR (SENSOR GROUND) WHT WIRE YEL WIRE

7.4L A/C COMP FUSE A/C COMPRESSOR CLUTCH RELAY ABS FUSE 4 AUX FAN FUSE RR DEFOG FUSE AUX PWR AUTO HEADLAP FUSE 22 AUXILIARY AUXILIARY MEDIUM HIGH BLOWER BLOWER MOTOR MOTOR RELAY RELAY AUXILIARY COOLING FAN RELAY AUXILIARY ROOF LAMP RELAY AUXILIARY ROOF LAMP SWITCH BLK WIRE BLOWER FUSE 3 BLU WIRE BRAKE CONTROL MODULE BREAKOUT) BRAKE LAMP RELAY UNDERHOOD FUSE-RELAY CENTER BREAKOUT GASOLINE-ENG HARN, BREAKOUT) CAMP/TRAIL FUSE CARGO LAMP SWITCH CONN CONVENIENCE CENTER CTSY FUSE 3 DIODE DRL/FOG FUSE 15 DUAL BATTERY ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE EVO/ PASSLOCK MODULE FROM LT GRN 6-PIN WIRE FRONT POWER REAR DOME OUTSIDE DOME REARVIEW LAMPS LAMPS MIRROR SWITCH FUEL PUMP OIL PRESSURE SWITCH AND SENDER FUEL PUMP RELAY UNDERHOOD FUSE-RELAY CENTER FUSIBLE LINK (10 GA-RUST) GARAGE OVERHEAD DOOR CONSOLE OPENER READING LAMPS GENERATOR (BASE) GENERATOR (UPLEVEL) HEADLAMP HEADLAMP AND PANEL DIMMER SWITCH HEADLAMP CONTROL MODULE HEATER AND A/C CONTROL SWITCH HEATER MIRROR RELAY HIGH AUXILIARY BLOWER LOW MOTOR BLOWER RELAY MOTOR RELAY HORN FUSE HORN RELAY UNDERHOOD LAMP UNDERHOOD FUSE- RELAY CENTER HTD MIR FUSE I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK INFLATABLE RESTRAINT SWITCH BREAKOUT) INSTRUMENT CLUSTER (POLICE RIGHT PACKAGE) VANITY MIRROR LEFT BATTERY (DIESEL) LEFT COURTESY LAMP LEFT VANITY MIRROR MEGA FUSE BLOCK NCA WIRE OR BLK 8-PIN IN-LINE WIRE ORG/ WIRE OVERHEAD FRONT INTERIOR CONSOLE DOME LAMP CONTROL READING LAMP MODULE LAMPS PANEL DIMMER SWITCH PICKUP ONLY PK LPS FUSE 9 POWERTRAIN CONTROL MODULE (DIESEL) RADIO BATT FUSE 19 AUX FUSE 22 RED WIRE REMOTE BATTERY STUD RIGHT BATTERY RIGHT COURTESY LAMP SECURITY/ STRG FUSE 21 SEO FUSE SINGLE BATTERY (BASE) SINGLE BATTERY (UPLEVEL) SPARE POWER SOURCE SPOTLAMP (POLICE PACKAGE) STARTER MOTOR SOLENOID STOP FUSE 2 LIGHTING FUSE 8 TO FUSIBLE LINK (DIAGRAM 5 OF 6) TO MEGAFUSE (DIAGRAM 6 OF 6) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 2 OF 6) UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL VEHICLE CONTROL MODULE (GASOLINE) W/O RKE 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

AUXILIARY POWER CENTER (CENTER OF DASH) BLK WIRE CICUIT BREAKER CUSTOMER INSTALLED OPTIONS FROM PWR WDO CIRCUIT BREAKER (DIAGRAM 2 OF 5) FROM RIGHT BATTERY (DIAGRAM 1 OF 5) FUSE FUSE BLOCK 3 FUSE BLOCK 4 FUSE BLOCK 5 FUSE FUSE GENERATOR (POLICE PACKAGE) MEGA FUSE ORG/ WIRE PNK WIRE POLICE PACKAGE RED WIRE RELAY RELAY/ FUSE RIGHT BATTERY WHT WIRE YEL WIRE

BLK WIRE BLU WIRE BRN WIRE CTSY FUSE 3 DOWN GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK ILLUM- NATION LAMP LEFT LEFT POWER OUTSIDE REARVIEW MIRROR LEFT/ RIGHT MOTOR LT (OR LT GRN WIRE ORG/ WIRE POWER OUTSIDE REARVIEW MIRROR SWITCH PPL/WHT WIRE RED WIRE RIGHT RIGHT POWER OUTSIDE REARVIEW MIRROR UP/ DOWN MOTOR YEL WIRE