GMC Pickup K2500 (1985-2000) anti-lock brakes system Wiring diagrams

AIR BAG IND ANTI- LOCK BRAKES IND ANTI-LOCK BRAKES SYSTEM BAT IND WAIT TO BLK WIRE BLK/WHT WIRE BRAKE IND BRN WIRE BRN/WHT WIRE CHECK GAUGES IND CHECK GAUGES LAMP DRIVER DAYTIME RUNNING LAMPS IND DK BLU WIRE DK GRN WIRE ENGINE CONTROLS SYSTEM FUEL GAUGE GENERATOR GRY WIRE HEADLIGHTS SYSTEM HI-BEAM IND IGN ILLUM ILLUMINATION IND INSTRUMENT CLUSTER LED DIMMING LEFT TURN IND RIGHT TURN IND LOW COOLANT IND LOW COOLANT LEVEL INDICATOR MODULE (BEHIND CENTER OF DASH) LOW COOLANT LEVEL SENSOR (IN COOLANT RESERVOIR, RIGHT SIDE OF ENGINE COMPT) LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE OIL PRESS OIL PRESSURE SWITCH, SENDER (UNDER INTAKE MANIFOLD, CENTER OF ENGINE) PARITY PRNDL PNK PNK WIRE PNK PPL WIRE PNK WIRE PPL PPL/WHT WIRE PRNDL PRNDL A PRNDL B PRNDL C SAFETY BELT IND SERVICE ENGINE SOON IND SERVICE THROTTLE SOON IND SOLID STATE SPEED- OMETER STARTING/CHARGING SYSTEM SUPPLEMENTAL RESTRAINTS SYSTEM TACH TAN WIRE TAN/WHT WIRE TEMP GAUGE TRANSMISSION RANGE SELECTOR (LEFT SIDE OF TRANSMISSION) UP- SHIFT IND (M/T) VOLT- METER WARNING SYSTEM WATER IN FUEL IND WATER-IN FUEL SENSOR (TOP REAR OF ENGINE) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

ACCY ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BRAKE IND IN BRAKE PRESSURE WARNING SWITCH (ON REAR OF EBCM CASTING) BRN WIRE BULB TEST DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ELECTRONIC BRAKE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) ENG-1 MINI FUSE ENGINE CONTROLS SYSTEM (FUEL PUMP BALANCE RELAY) ENGINE CONTROLS SYSTEM TRANSMISSION SYSTEM ENGINE CONTROLS SYSTEM FUEL GAGE SENDER (IN FRONT FUEL TANK) FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE OF FRAME RAIL) FUEL PUMP/ SENDER GAUGES FUSE 4 GRN WIRE HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT END OF DASH) IGN E MINI FUSE IGN SW BRAKE IND BRAKE PSI PK BRAKE 33 33 IGNITION SWITCH LOCK OFF LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE M/T A/T PARK BRAKE WARNING SWITCH (ON PARKING BRAKE PEDAL BRACKET) PNK PNK WIRE PNK PPL WIRE PNK WIRE PPL PPL/WHT WIRE RADIO RUN WIRE SECONDARY FUEL GAGE SENDER (IN REAR FUEL TANK) SINGLE FUEL TANK DUAL FUEL TANKS TAN/WHT WIRE TRANS FUSE 20 TWISTED PAIR UNDERHOOD FUSE-RELAY CENTER (LEFT REAR OF ENGINE COMPT) UNDERHOOD FUSE-RELAY CENTER (LEFT REAR OF ENGINE COMPT) DIODE 1 VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION OR TRANSFER CASE) VEHICLE SPEED SENSOR (VSS) ADAPTER VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF DASH) WHT TAN/ WIRE WHT WIRE YEL/BLK WIRE

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

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 AXLE SIG 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 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 PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) PPL/WHT WIRE RED WIRE RED/WHT WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANS- MISSION CIRCUIT 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 TURN SIGNAL SWITCH WHT WIRE YEL WIRE YEL/BLK 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 AXLE SIG 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 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 PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) PPL/WHT WIRE RED WIRE RED/WHT WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY TAN/BLK WIRE TCASE FUSE 2 TCC/STOP LAMP SWITCH (TOP OF BRAKE PEDAL) TRANS- MISSION CIRCUIT 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 TURN SIGNAL SWITCH WHT WIRE YEL WIRE YEL/BLK WIRE

A/T ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE DIESEL FROM ABS CONTROL MODULE) FRONT AXLE ACTUATOR FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HEAVY-DUTY TRANSFER CASE HOT IN PARK OR HEAD HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR INTERIOR LIGHTS SYSTEM (SUBURBAN W/ A/C ONLY) LT BLU WIRE LT N/A M/T POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE SEAT BELT SWITCH TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE RELAY (RIGHT SIDE OF FIREWALL) TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) WHT WIRE

A/T ANTI-LOCK BRAKES SYSTEM BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE DIESEL FROM ABS CONTROL MODULE) FRONT AXLE ACTUATOR FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HEAVY-DUTY TRANSFER CASE HOT IN PARK OR HEAD HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR INTERIOR LIGHTS SYSTEM (SUBURBAN W/ A/C ONLY) LT BLU WIRE LT N/A M/T POWERTRAIN CONTROL MODULE (DIESEL) RED WIRE SEAT BELT SWITCH TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE RELAY (RIGHT SIDE OF FIREWALL) TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) WHT 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

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

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