GMC Pickup C2500 (1985-2000) dk grn Wiring diagrams

419 456 389 5 15 4 MIL IND UPSHIFT IND SPEEDO ACCY BULB TEST LOCK OFF ANTI- LOCK BRAKES IND ANTI-LOCK BRAKES SYSTEM BAT IND BLK WIRE BLK/WHT WIRE BRAKE IND BRAKE PRESSURE WARNING SWITCH (ON REAR OF EBCM CASTING) BRN WIRE BRN/WHT WIRE CHECK GAUGES IND CHECK GAUGES LAMP DRIVER DAYTIME RUNNING LAMPS IND AIR BAG IND DAYTIME RUNNING LAMPS MODULE (BEHIND LEFT SIDE OF DASH, TAPED TO DASH HARNESS) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ENGINE CONTROLS SYSTEM (FUEL PUMP BALANCE RELAY) ENGINE COOLANT TEMPERATURE SENDER (LEFT CYLINDER HEAD) FUEL GAUGE FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE FRAME RAIL) FUEL PUMP, SENDER (IN FRONT FUEL TANK) FUEL PUMP, SENDER (IN FUEL TANK) GRN WIRE GRY WIRE HEADLIGHTS SYSTEM HI-BEAM IND HOT IN RUN OR START HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK (LEFT END OF DASH) GAUGES FUSE 4 IGN IGN E MINI FUSE IGN SW BRAKE IND BRAKE PSI PK BRAKE 33 33 IGNITION COIL (RIGHT REAR OF ENGINE) IGNITION SWITCH ILLUM ILLUMINATION INSTRUMENT CLUSTER LED DIMMING LEFT TURN IND LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE M/T A/T PNK WIRE OIL GAUGE PARITY PRNDL 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 GAGE SENDER (IN REAR FUEL TANK) SENS RTRN FUEL IN SERVICE ENGINE SOON IND SINGLE FUEL TANK DUAL FUEL TANKS STARTING/CHARGING SYSTEM SUPPLEMENTAL RESTRAINTS SYSTEM TACH TAN WIRE TAN/BLK WIRE TAN/WHT WIRE TEMP GAUGE TRANS FUSE 20 TRANSMISSION RANGE SELECTOR (LEFT SIDE OF TRANSMISSION) TWISTED PAIR UNDERHOOD FUSE-RELAY CENTER UPSHIFT IND (M/T ONLY) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR OF TRANSMISSION OR TRANSFER CASE) VEHICLE SPEED SENSOR (VSS) ADAPTER VOLTMETER SPEEDOMETER WARNING SYSTEMS WHT TAN/ WIRE WHT WIRE YEL 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

39 (OR 1020) AIR BAG IND ANTI- LOCK BRAKES IND ANTI-LOCK BRAKES SYSTEM ANTI-THEFT SYSTEM BLK WIRE BLK/WHT WIRE BRAKE IND BRN WIRE BRN/WHT WIRE CHECK GAUGES IND CHECK GAUGES LAMP DRIVER DAYTIME RUNNING LAMPS IND DIMMING LED DK BLU WIRE DK GRN WIRE ENGINE CONTROLS SYSTEM FUEL GAUGE FUEL PUMP/ OIL PRESSURE SWITCH, SENDER (UNDER INTAKE MANIFOLD, CENTER OF ENGINE) GENERATOR GRY WIRE HEADLIGHTS SYSTEM HI-BEAM IND IGN ILLUMINATION IND INSTRUMENT CLUSTER LOW COOLANT IND LOW COOLANT LEVEL INDICATOR MODULE (BEHIND CENTER OF DASH) LOW COOLANT LEVEL SWITCH (IN COOLANT RESERVOIR, RIGHT SIDE OF ENGINE COMPT) LT BLU WIRE LT GRN WIRE LT GRN/BLK WIRE OIL PRESS PNK PNK WIRE PNK PPL WIRE PNK WIRE PPL PPL/WHT WIRE PRNDL PRNDL A PRNDL B PRNDL C PRNDL PARITY RIGHT TURN IND LEFT TURN IND SAFETY BELT IND SECURITY 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 SWITCH (LEFT SIDE OF TRANSMISSION) VOLT- METER WAIT TO BAT IND WARNING SYSTEMS WATER IN FUEL IND WATER IN-FUEL SENSOR (ON FUEL FILTER/ MANAGER) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

A/C REQUEST SIGNAL AIR CONDITIONING SYSTEM AIR INLET VLV MTR CTLR AUTOMATIC AUTOMATIC TRANSFER CASE SHIFT CONTROLLER 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 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 GRN WIRE DK GRN/WHT WIRE 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 IGNITION COIL (TOP RIGHT REAR OF ENGINE) IGNITION CONTROL MODULE (RIGHT SIDE REAR OF ENGINE) IGNITION FEED IGN TIMING SIG. IGN COIL OUT IGNITION PRESSURE SWITCH INPUT PRESSURE SWITCH INPUT LT BLU/BLK WIRE LT BLU/WHT WIRE LT DK VSS SERIAL INPUT DATA SIG MANUAL OR SELECTABLE 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 SHIFT IND LP OUT EGR VLV FEED SPEED SENSOR SPEED STOPLAMP/ VCM SENSOR CLUTCH SIG INPUT SWITCH INPUT STOPLAMP SWITCH (TOP OF BRAKE PEDAL) SWITCH SIGNAL TAN/BLK WIRE TRANSFER CASE CONTROL MODULE (UNDER DASH ON STEERING COLUMN SUPPORT BRACKET) TRANSFER CASE SWITCH (LEFT TOP OF TRANSFER CASE) 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

1-2 SHIFT SOL 2-3 SHIFT SOL 12 7 8 9 10 VSS SIG VSS RTN GROUND IGN VSS SIG 1226 1225 RANGE MODE SEL C RANGE MODE SEL B RANGE MODE SEL A 13 14 15 VSS HI VSS OUTPUT VSS OUTPUT 27 28 29 30 31 PPL A/C REQUEST SIG A/C SYSTEM A/T FLUID PRESSURE (TFP) MANUAL VALVE POSITION SWITCH ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT (M/T) WIRE BRN/WHT WIRE CRUISE CONTROL SYSTEM DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK WIRE ECT TEMP SENS IN GRN WIRE GRY WIRE GRY/BLK WIRE INLINE GENDER ADAPTER INTAKE MAN AIR TEMP SENS APP 2 SIG GLOW PLUG RELAY FORCE MTR LOW LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT PNK WIRE LT PPL LT PPL PPL MAP SENS INPUT FORCE MTR HI NCA WIRE ORG/ WIRE ORG/BLK WIRE OTHERS PNK PNK 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (BEHIND RIGHT SIDE OF DASH, NEAR BLOWER MOTOR) PPL PPL (A/T) BRAKE SW IN BRAKE SWITCH INPUT CRUISE CTRL SW ENGAGE PPL (OR BRN/WHT) WIRE PPL/WHT WIRE PRESSURE CONTROL SOLENOID VALVE RADIO, EVO/ PASSLOCK CONTROL MODULE, TRANSFER CASE CONTROL MODULE RED WIRE RED/BLK WIRE SENSOR GND TAN WIRE TAN/BLK WIRE TIMING STEPPER MTR (HIGH) 3 MODE CRUISE PPL SENSOR GND SENSOR GND APP 1 SIG TIMING STEPPER MTR (LOW) TIMING STEPPER MTR (LOW) TORQUE CONVERTER CLUTCH PULSE WDTH MOD SOL TRANSMISSION SPEED INPUT TRANSMISSION TEMP INPUT TRANSMISSION TEMPERATURE SENSOR TRANSMISSIONS SYSTEM VEHICLE SPEED SENSOR (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF DASH) VSS VSS LO HI WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

27 28 29 30 31 PPL 5 VOLT REF ACCELERATOR PEDAL POSITION (APP) MODULE (PART OF ACCELERATOR PEDAL) BLK WIRE BLU WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION (CPP) SWITCH (M/T ONLY) (TOP OF CLUTCH PEDAL BRACKET) CMP SIG DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK WIRE ECM 1 FUSE ELECTRONIC BRAKE CONTROL MODULE (ON LEFT SIDE OF ENGINE COMPT) ENGINE SHUTOFF SOLENOID (TOP OF FUEL INJECTION PUMP) GRN WIRE GRY WIRE HIGH RES SIG HOT AT ALL TIMES HOT IN HOT IN RUN OR START I/P FUSE BLOCK INJECTION TIMING STEPPER MOTOR (TOP RIGHT FRONT OF ENGINE) LT BLU WIRE LT GRN WIRE LT PPL NCA WIRE OPTICAL FUEL TEMPERATURE SENSOR (ON TOP OF FUEL INJECTION PUMP) ORG/ WIRE ORG/BLK WIRE PNK PNK 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK PNK 8 9 WIRE PNK PNK PPL WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE POWER DISTRIBUTION SYSTEM PPL PPL (OR BRN/WHT) WIRE RED WIRE RED/BLK WIRE RUN WIRE SENS GRD STOP- LAMP SWITCH (ON TOP OF BRAKE PEDAL) STOP/HAZ FUSE 1 TAN WIRE TAN/BLK WIRE TRANS FUSE 20 UNDERHOOD FUSE/RELAY CENTER WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

"GLOW PLUGS" INDICATOR BLK WIRE BLK/WHT WIRE BLU WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B FUSE FUEL BALANCE PUMP FUEL GAUGE FUEL PUMP BALANCE MODULE (INSIDE LEFT SIDE FRAME RAIL) FUEL PUMP BALANCE RELAY (ON FUEL PUMP BALANCE MODULE) FUEL PUMP PRIME CONNECTOR (LEFT SIDE OF ENG COMPT) FUEL PUMP RELAY (IN UNDER FUSE- RELAY CENTER) FUEL PUMP/OIL PRESSURE SWITCH GAUGES FUSE 4 GRN WIRE GRY WIRE HOT AT ALL TIMES UNDERHOOD FUSE/RELAY CENTER HOT IN RUN OR START I/P FUSE BLOCK IGN E FUSE INSTRUMENT CLUSTER INSTRUMENT CLUSTER SYSTEM LT BLU WIRE LT GRN WIRE NCA WIRE ORG/ WIRE PNK PNK 8 9 WIRE PNK PNK PNK WIRE PNK WIRE PPL PRIMARY TANK FUEL LEVEL SENSOR RED WIRE SERVICE ENGINE SOON INDICATOR SERVICE THROTTLE SOON INDICATOR TAN WIRE VEHICLE SPEED INPUT W/ DUAL TANKS W/O DUAL TANK W/O DUAL TANK W/ DUAL TANKS WAIT TO WATER IN FUEL INDICATOR WATER IN-FUEL SENSOR (ON FUEL FILTER/ MANAGER) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1226 1225 RANGE MODE SEL C RANGE MODE SEL B RANGE MODE SEL A 27 28 29 30 31 PPL 3/2 SHIFT SOL. PRESSURE CONTROL SOLENOID VALVE 7 8 9 10 12 13 14 15 VSS RTN GROUND A/C REQUEST SIG A/C SYSTEM A/T FLUID PRESSURE (TFP) MANUAL VALVE POSITION SWITCH ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BOOST PRESSURE SENSOR BRN WIRE BRN/WHT (M/T) WIRE BRN/WHT WIRE CRUISE CONTROL SWITCH DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE DK PNK WIRE ECT TEMP SENS IN BARO SENSOR INPUT GRN WIRE GRY WIRE GRY/BLK WIRE INTAKE MAN AIR TEMP SENS APP 2 SIG GLOW PLUG RELAY FORCE MTR LOW LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT PNK WIRE MAP SENS INPUT FORCE MTR HI NCA WIRE ORG/ WIRE ORG/BLK WIRE PNK PNK 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE (PCM) (BEHIND RIGHT SIDE OF DASH, NEAR BLOWER MOTOR) PPL PPL (A/T) BRAKE SW IN BRAKE SWITCH INPUT CRUISE CTRL SW ENGAGE PPL (OR BRN/WHT) WIRE PPL/WHT WIRE RADIO RED WIRE RED/BLK WIRE RESUME SENSOR GND SET- SHIFT SOL. SHIFT SOL. TAN WIRE TAN/BLK WIRE TIMING STEPPER MTR (HIGH) 3 MODE CRUISE PPL SENSOR GND SENSOR GND APP 1 SIG TIMING STEPPER MTR (LOW) TIMING STEPPER MTR (LOW) TRANSMISSION SPEED INPUT TRANSMISSION TEMP INPUT TRANSMISSION TEMPERATURE SENSOR TRANSMISSIONS SYSTEM VEHICLE SPEED SENSOR BUFFER (BEHIND RIGHT SIDE OF DASH) VSS SIG VSS SIG VSS HI VSS OUTPUT VSS OUTPUT WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

27 28 29 30 31 PPL 5 VOLT REF ACCELERATOR PEDAL POSITION (APP) MODULE (PART OF ACCELERATOR PEDAL) BLK WIRE BLU WIRE BRAKE FUSE 18 BRAKE SWITCH ASSEMBLY (AT REAR OF BRAKE PEDAL SUPPORT BRACKET) BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION (CPP) SWITCH (M/T ONLY) (TOP OF CLUTCH PEDAL) CMP SIG DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM 1 FUSE ELECTRONIC BRAKE CONTROL MODULE (ON LEFT SIDE OF ENGINE COMPT) GRN WIRE GRY WIRE HIGH RES SIG HOT AT ALL TIMES HOT IN HOT IN RUN OR START I/P FUSE BLOCK INJECTION TIMING STEPPER MOTOR (TOP RIGHT FRONT OF ENGINE) LT BLU WIRE LT GRN WIRE LT PPL NCA WIRE ORG/ WIRE ORG/BLK WIRE PNK PNK 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 WIRE PNK PNK 8 9 WIRE PNK PNK PNK WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE POWER DISTRIBUTION SYSTEM PPL PPL (OR BRN/WHT) WIRE RED WIRE RED/BLK WIRE RUN WIRE SENS GRD STOP/HAZ FUSE 1 TAN WIRE TAN/BLK WIRE TRANS FUSE 20 UNDERHOOD FUSE-RELAY CENTER WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

"GLOW PLUGS" INDICATOR BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B FUSE FUEL LIFT PUMP (INSIDE LEFT FRAME RAIL, BELOW DRIVER'S DOOR) FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (IN UNDERHOOD FUSE-RELAY CENTER) GAUGES FUSE 4 GRN WIRE GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK INSTRUMENT CLUSTER INSTRUMENT CLUSTER SYSTEM INSTRUMENT CLUSTER SYSTEM (FUEL PUMP BALANCE RELAY) LT GRN WIRE ORG/ WIRE PNK PNK 8 9 WIRE PNK PNK PNK WIRE PNK WIRE RED WIRE SERVICE ENGINE SOON INDICATOR SERVICE THROTTLE SOON INDICATOR TAN WIRE UNDERHOOD FUSE-RELAY CENTER VEHICLE SPEED INPUT W/DUAL TANKS W/O DUAL TANKS WAIT TO WATER IN FUEL INDICATOR WATER IN-FUEL SENSOR (TOP CENTER REAR OF ENGINE) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE