GMC Pickup K2500 (1985-2000) blk/wht Wiring diagrams

39 (OR 1020) 7.4L VIN J ONLY 900 419 507 389 12 5 15 4 FUEL RET MIL IND UPSHIFT IND SPEEDO ACCY ANTI- LOCK BRAKES IND ANTI-LOCK BRAKES SYSTEM ANTI-THEFT SYSTEM BAT IND HI BEAM IND BLK WIRE BLK/WHT WIRE BRAKE IND BRAKE PRESSURE WARNING SWITCH (ON UNDERSIDE OF ELECTRONIC BRAKE CONTROL MODULE) BRN WIRE BRN/WHT WIRE CHECK GAUGES IND CHECK GAUGES LAMP DRIVER CONVENIENCE CENTER DAYTIME RUNNING LAMPS IND AIR BAG IND DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE (EBCM) (ON LEFT SIDE OF ENGINE COMPT) ENGINE CONTROLS SYSTEM (FUEL PUMP BALANCE RELAY) FUEL GAUGE FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE OF FRAME RAIL) FUEL PUMP, SENDER (IN FUEL TANK) GRN WIRE GRY WIRE HEADLIGHTS SYSTEM HOT IN RUN OR START I/P FUSE BLOCK GAUGES FUSE 4 HOT IN RUN, BULB TEST OR START IGN IGN E MINI FUSE IGN SW BRAKE IND BRAKE PSI PK BRAKE 33 33 IGNITION COIL (TOP LEFT REAR OF ENGINE) IGNITION SWITCH ILLUMINATION INSTRUMENT CLUSTER LED DIMMING LEFT TURN IND LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE M/T A/T PNK WIRE MALFUNC- TION INDICATOR LAMP NCA WIRE PARITY PRNDL PARK BRAKE SWITCH (ON PARK BRAKE PEDAL BRACKET) PNK WIRE PPL PPL 9 29 30 FUEL VSS VSS PPL/WHT WIRE PRNDL PRNDL A PRNDL B PRNDL C RIGHT TURN IND RUN WIRE SAFETY BELT IND SECONDARY FUEL GAUGE SENDER (IN REAR FUEL TANK) SECURITY IND SENS RTRN FUEL IN SERVICE ENGINE SOON SINGLE FUEL TANK DUAL FUEL TANKS SPEEDOMETER STARTING/CHARGING SYSTEM SUPPLEMENTAL RESTRAINTS SYSTEM TACH TAN WIRE TAN/WHT WIRE TEMP GAUGE OIL GAUGE TRANS FUSE 20 TRANSMISSION RANGE SWITCH TWISTED PAIR UNDERHOOD FUSE BLOCK UPSHIFT IND (M/T ONLY) VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT SIDE OF TRANSMISSION, LEFT SIDE OF TRAN- VEHICLE SPEED SENSOR (VSS) ADAPTER VOLTMETER WARNING SYSTEMS WHT WIRE YEL WIRE

4.3L A/C COMPRESSOR CLUTCH A/C COMPRESSOR CYCLING SWITCH A/C HIGH PRESSURE (NOT CUTOUT USED) SWITCH AIR REACTION INJECTION (SECONDARY) WATER PUMP VALVE (7.4L ONLY) BALANCE FUEL FUEL PUMP GAGE BALANCE SENDER MODULE BLK WIRE BLK/WHT WIRE BLOWER MOTOR BRAKE PRESSURE WARNING SWITCH CRUISE INSTRUMENT CONTROL CLUSTER MODULE DATA LINK CONNECTOR DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE EVAPORATIVE EMISSIONS PURGE VACUUM SOLENOID SWITCH EXCEPT 4.3L FRONT AXLE ACTUATOR FRONT MODE DOOR MOTOR FRONT TEMPERATURE DOOR MOTOR FUEL PUMP AND SENDER GASOLINE HEATED OXYGEN SENSOR BANK 1 SENSOR 1 HEATED OXYGEN SENSOR BANK 1 SENSOR 2 HEATED OXYGEN SENSOR BANK 2 SENSOR 1 HEATED OXYGEN SENSOR BANK 2 SENSOR 2 HIGH A/C PRESSURE CUTOUT SWITCH HIGH BLOWER MOTOR RELAY IGNITION COIL MODULE MASS AIRFLOW SENSOR PARK/ NEUTRAL POSITION SWITCH POWER STEERING CONTROL MODULE RECIRCULATION DOOR MOTOR STARTER RELAY STOPLAMP RELAY TRANSFER CASE RELAY TRANSFER CASE RELAY BREAKOUT) UNDER- HOOD LAMP UNDERHOOD FUSE- RELAY CENTER A/C COMPRESSOR CLUTCH RELAY UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE VEHICLE UNDER- SPEED HOOD SENSOR REEL (BLUNT CUT) LAMP W/ DUAL TANKS W/O DUAL TANKS (EXCEPT 4.3L) UNDERHOOD FUSE- RELAY CENTER FUEL PUMP RELAY

4.3L ONLY BALANCE FUEL GAGE SENDER BENCH OTHERS SEAT BLK WIRE BLK/WHT WIRE CENTER HIGH MOUNT STOP LAMP CONVENIENCE CENTER CONVENIENCE CENTER (UNDER LEFT SIDE OF I/P) DATA LINK CONNECTOR DIESEL DOOR LOCK RELAY ELECTROCHROMIC REARVIEW MIRROR W/ COMPASS FOUR-WHEEL DRIVE INDICATOR LAMP FUEL GAGE SENDER FUEL PUMP AND SENDER FUEL PUMP BALANCE MODULE INSTRUMENT CLUSTER INTERIOR LAMP CONTROL MODULE LEFT CLEARANCE LAMP LEFT FRONT POWER WINDOW LOCK SWITCH LEFT ILLUMINATED VANITY MIRROR LEFT POWER LUMBAR SUPPORT MOTOR LEFT REAR REAR POWER WINDOW WINDOW LOCKOUT SWITCH SWITCH MASS AIRFLOW SENSOR POWER AMPLIFIER POWER AMPLIFIER RELAY POWER FUEL STEERING PUMP CONTROL RELAY MODULE POWER OUTSIDE REARVIEW MIRROR SWITCH POWERTRAIN CONTROL MODULE REMOTE CONTROL DOOR LOCK RECEIVER RIGHT CLEARANCE LAMP RIGHT FRONT POWER WINDOW SWITCH RIGHT ILLUMINATED VANITY MIRROR RIGHT POWER LUMBAR SUPPORT MOTOR RIGHT POWER POWER LEFT POWER LUMBAR MOTOR SEAT RIGHT REAR POWER WINDOW SWITCH ROOF MARKER LAMPS SEAT BELT SWITCH TAN/WHT WIRE TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP UNDER HOOD FUSE-RELAY CENTER VEHICLE SPEED SENSOR BUFFER WHT/ BLK WIRE

AUXILIARY HEATER- A/C LOGIC MODULE BALANCE FUEL PUMP BLK WIRE BLK/WHT WIRE CENTER HIGH MOUNT STOPLAMP CHASSIS CAB, HEAVY DUTY DOOR CONTACT BUTTON DOOR LOCK CONTROL MODULE EXCEPT CHASSIS CAB, HEAVY DUTY FRONT AUXILIARY HEATER-A/C CONTROL MODULE FRONT REAR DOME DOME LAMP LAMP FUEL LIFT PUMP INFLATABLE RESTRAINT FRONT END SENSOR INFLATABLE RESTRAINT SENSING AND DIAGNOSTIC MODULE LEFT CARGO DOOR DEFOGGER GRID LEFT LEFT REAR FRONT CLEARANCE CLEARANCE LAMP LAMP LEFT REAR FENDER LEFT REAR TAIL, STOP, LICENSE, TURN, BACKUP LAMPS LEFT REAR TAIL, STOP, TURN, LEFT BACKUP LICENSE LAMP LAMPS LEFT TAIL, STOP, LEFT TURN, LICENSE BACKUP LAMPS LAMP OVERHEAD CONSOLE LAMPS PICKUP W/ DUAL REAR WHEELS REAR AUXILIARY HEATER-A/C CONTROL MODULE REAR AUXILIARY MODE DOOR MOTOR REAR AUXILIARY TEMP DOOR MOTOR REAR BLOWER MOTOR REAR LIFTGATE WINDOW DEFOGGER GRID REAR WIPER MOTOR MODULE RIGHT CARGO DOOR DEFOGGER GRID RIGHT ENDGATE LICENSE MARKER LAMP LAMPS RIGHT LICENSE LAMP RIGHT REAR DOOR JAMB SWITCH RIGHT REAR FENDER RIGHT REAR TAIL, STOP, LICENSE, TURN, BACKUP LAMPS RIGHT REAR TAIL, STOP, TURN, BACKUP LAMPS RIGHT RIGHT REAR FRONT CLEARANCE CLEARANCE LAMP LAMP RIGHT TAIL, STOP, TURN, BACKUP LAMPS SUBURBAN/ UTILITY TRAILER GROUND (TAPED BACK) UTILITY ONLY W/ DUAL TANKS WHT 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

BATT B BELT SWITCH BREAKOUT) BLK WIRE BLK/WHT WIRE CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) DOOR LOCK RELAY (UNDER CENTER OF DASH, NEAR REMOTE CONTROL DOOR LOCK RECEIVER) DRIVER DR UNLK UNLOCK OUT HORN SIGNAL GAUGES FUSE 4 GROUND GRY WIRE HORNS SYSTEM HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT SIDE OF DASH, INTERIOR LAMPS SYSTEM LEFT DOOR LOCK SWITCH LEFT FRONT DOOR LOCK ACTUATOR LOCK LOCK OUT DOME LAMPS LT BLU WIRE ORG/ WIRE PASS DRS UNLK PNK IGNITION DOME LMP OFF PROGRAM SIG WIRE PNK WIRE PWR ACCY C.B. REMOTE CONTROL DOOR LOCK RECEIVER (UNDER CENTER OF DASH PANEL) RIGHT DOOR LOCK SWITCH RIGHT FRONT DOOR LOCK ACTUATOR SEAT BELT SWITCH BREAKOUT) TAN WIRE UNLOCK W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE

5 CM FROM TRANSFER CASE BREAKOUT) A/T BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FROM ENGINE HARN BREAKOUT) FRONT AXLE ACTUATOR (RIGHT REAR OF FRONT DRIVE AXLE) FRONT AXLE SWITCH (RIGHT REAR OF FRONT DRIVE AXLE) FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HOT IN RUN HOT WITH HEADLAMP SW IN PARK OR HEAD I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR LT BLU WIRE POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY (EXC DIESEL) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE RELAY TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER

5 CM FROM TRANSFER CASE BREAKOUT) A/T BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FROM ENGINE HARN BREAKOUT) FRONT AXLE ACTUATOR (RIGHT REAR OF FRONT DRIVE AXLE) FRONT AXLE SWITCH (RIGHT REAR OF FRONT DRIVE AXLE) FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HOT IN RUN HOT WITH HEADLAMP SW IN PARK OR HEAD I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR LT BLU WIRE POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY (EXC DIESEL) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE RELAY TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER

5 CM FROM TRANSFER CASE BREAKOUT) A/T BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FROM ENGINE HARN BREAKOUT) FRONT AXLE ACTUATOR (RIGHT REAR OF FRONT DRIVE AXLE) FRONT AXLE SWITCH (RIGHT REAR OF FRONT DRIVE AXLE) FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HOT IN RUN HOT WITH HEADLAMP SW IN PARK OR HEAD I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR LT BLU WIRE POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY (EXC DIESEL) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE RELAY TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER

A/C REQUEST SIGNAL A/T AIR CONDITIONING SYSTEM AIR INLET VLV MTR CTLR BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION (CPP) SWITCH (AT TOP OF CLUTCH PEDAL BRACKET) CPP SW INPUT FOUR WHL DR SIG LO CRUISE CTRL SIG ENG 23 24 A/T CRUISE CONTROL MODULE (LEFT REAR OF ENGINE COMPT, ON FIREWALL) DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH, LEFT SIDE OF STEERING COLUMN) DISTRIBUTOR DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE EGR VLV FEED ELECTRONIC VARIABLE ORIFICE/ PASSLOCK CONTROL MODULE (CENTER OF DASH) FORCE MOTOR FEED TRANS INPUT SPEED RTN TRANS INPUT SPEED SIG EST OUTPUT SIG FORCE MOTOR RETURN GROUND GROUND SENSOR GROUND FUEL LEVEL INPUT SWITCH SIGNAL FUEL PUMP PRIME CONNECTOR (LEFT REAR OF ENG COMPT) FUEL PUMP RELAY FUEL PUMP RLY CTRL 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 GRN WIRE GROUND GRY WIRE GRY/BLK WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES UNDERHOOD FUSE- RELAY CENTER ECMB FUSE HOT IN RUN I/P FUSE BLOCK IGN BRAKE INPUT INPUT SW INPUT IGNITION COIL IGNITION CONTROL MODULE (ON REAR OF INTAKE MANIFOLD) IGNITION FEED IGN TIMING SIG. IGN COIL OUT IGNITION PRESSURE SWITCH INPUT PRESSURE SWITCH INPUT LT BLU/BLK WIRE LT BLU/WHT WIRE LT VSS SERIAL INPUT DATA SIG MANUAL OR AUTOMATIC ORG/ WIRE PNK IGNITION FOUR WHL DR SIG EGR VLV GROUND WIRE PNK PNK PNK WIRE PNK WIRE PPL PPL (OR PPL A/T M/T PPL PPL PPL PPL 420 OR PPL/WHT WIRE PRESSURE SWITCH INPUT RADIO RED WIRE RED/BLK WIRE SENSOR RETURN SPEED SENSOR SPEED STOPLAMP/ VCM SENSOR CLUTCH SIG INPUT SWITCH INPUT STOPLAMP SWITCH (TOP OF BRAKE PEDAL) SWITCH SIGNAL TRANSFER CASE CONTROL MODULE (UNDER DASH ON STEERING COLUMN SUPPORT BRACKET) UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VSS SIG OUT VSS SIG OUT CHECK ENG LP CTRL 389 419 WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE