GMC Pickup K2500 (1985-2000) yel 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

1-2 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID A/T ISS HI IN A/T ISS LO IN AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRAKE SWITCH ASSEMBLY (ON BRAKE PEDAL BRACKET) BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DATA CLASS II DK BLU WIRE ECM 1 FUSE ECM-B FUSE ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE ENG 1 FUSE FRONT WHEEL LOCK FUEL INJECTORS, IGNITION CONTROL MOUDULE, IGNITION COIL FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HEADLAMP, PANEL DIMMER SWITCH PNK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK IGNITION IN INSTRUMENT CLUSTER LEFT REAR SIDE LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MAF SENSOR, HEATED OXYGEN SENSORS MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL HI SOLENOID LO RANGE SIGNAL "A" RANGE SIGNAL "B" RANGE SIGNAL "C" RED WIRE RED/BLK WIRE SENSOR GROUND SENSOR RETURN TAN WIRE TCC PWM SOL TCC PWM SOLENOID THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TP SENS INPUT TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANS RANGE SWITCHES TRANS TEMP SIG IN TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR VEHICLE SPEED SENSOR ADAPTOR VSS HI VSS LO YEL WIRE YEL/BLK 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 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

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

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 COOLING FAN RELAY BLK WIRE BLOWER FUSE 3 BLU WIRE BODY CONTROL MODULE (BCM) BRAKE CONTROL MODULE BREAKOUT) BRAKE LAMP RELAY UNDERHOOD FUSE BLOCK BREAKOUT GASOLINE-ENG HARN, BREAKOUT) CAMP/TRAIL FUSE CONN CONVENIENCE CENTER CTSY FUSE 3 DIODE DK BLU/WHT WIRE DRL/FOG FUSE 15 DUAL BATTERY ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE FROM LT GRN 6-PIN WIRE FRONT REAR DOME DOME LAMPS LAMPS FUEL PUMP OIL PRESSURE SWITCH FUEL PUMP RELAY UNDERHOOD FUSE BLOCK FUSIBLE LINK (5 GA-RUST) GARAGE OVERHEAD DOOR CONSOLE OPENER READING LAMPS GENERATOR (BASE) GENERATOR (UPLEVEL) HEADLAMP HEADLAMP AND PANEL DIMMER SWITCH HEADLAMP CONTROL MODULE HEATER MIRROR RELAY HIGH BLOWER MOTOR RELAY HORN FUSE HORN RELAY UNDERHOOD LAMP UNDERHOOD FUSE BLOCK HTD MIR FUSE HVAC CONTROL MODULE I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK INFLATABLE RESTRAINT SWITCH BREAKOUT) INTERIOR LAMP CONTROL MODULE LEFT BATTERY (DIESEL) LEFT CARGO COURTESY LAMP LAMP SWITCH LEFT RIGHT VANITY VANITY MIRROR MIRROR LUXURY ONLY MEGA FUSE BLOCK NCA WIRE OR BLK 8-PIN IN-LINE WIRE ORG/ WIRE OVERHEAD FRONT CONSOLE DOME READING LAMP LAMPS PANEL DIMMER SWITCH PICKUP ONLY PK LPS FUSE 9 POWER OUTSIDE REARVIEW MIRROR SWITCH POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE REMOTE BATTERY STUD RIGHT BATTERY RIGHT COURTESY LAMP RIGHT FRONT DOOR COURTESY LAMP SECURITY/ STRG FUSE 21 SEO FUSE SINGLE BATTERY (BASE) SINGLE BATTERY (UPLEVEL) SPARE POWER SOURCE STARTER MOTOR SOLENOID STOP FUSE 2 LIGHTING FUSE 8 TO FUSIBLE LINK (DIAGRAM 5 OF 5) TO UNDERHOOD FUSE BLOCK (DIAGRAM 2 OF 5) UNDERHOOD FUSE BLOCK VEHICLE CONTROL MODULE (GASOLINE) W/O REAR AUXILIARY HEATER OR A/C W/O RKE YEL WIRE

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

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

2-HI IND 2-HI SW 4 LO INDIC CTRL 4 LO SW 4 LOW SELECT SW IN 2 HI SELECT SW IN 4 HI SELECT SW IN BATTERY IN 4-HI IND 4-HI SW 4-LO IND ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CHANNEL A CHANNEL B CHANNEL C CHANNEL P DATA LINK CONNECTOR (PARTIAL) (UNDER LEFT SIDE OF DASH) DIESEL DK BLU/WHT WIRE DK GRN/WHT WIRE ENGINE CONTROLS, CRUISE CONTROL, SOUND SYSTEMS, INSTRUMENT CLUSTER EXTERIOR LIGHTS FRONT AXLE ACTUATOR FRONT AXLE SWITCH FUSE 24 GASOLINE GAUGES FUSE 4 GROUND GROUND GROUND BATTERY IN BATTERY IN PNP SW-P/N IN GRY WIRE GRY/BLK WIRE HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) IGNITION IN ENCODER GROUND GROUND 2 HI INDIC CTRL 4 HI INDIC CTRL ILLUMINATION LAMP LOW SIG LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE OUTPUT VSS PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) (BEHIND RIGHT SIDE OF DASH) PPL/WHT WIRE RED WIRE RED/WHT WIRE SIG AXLE SPARE POWER SOURCE AUXILIARY BATTERY RELAY TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANSFER CASE CONTROL MODULE (STEERING COLUMN BRACKET) TRANSFER CASE ENCODER (RIGHT SIDE CENTER OF TRANSFER CASE) TRANSFER CASE ENCODER MOTOR (RIGHT SIDE OF TRANSFER CASE) TRANSFER CASE SELECT SWITCH TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TURN B/U FUSE 16 VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR BUFFER (DIESEL) (RIGHT SIDE OF DASH) YEL WIRE YEL/BLK WIRE

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