GMC Pickup C3500 (1985-2000) gry 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 SHIFT SOL 1-2 SHIFT SOLENOID 2-3 SHIFT SOL 2-3 SHIFT SOLENOID 3-2 CTRL SOLENOID 3-2 DOWNSHIFT SOL AUTOMATIC TRANSMISSION BATTERY IN BLK WIRE BLK/WHT WIRE BLU WIRE BRAKE FUSE 18 BRAKE SWITCH INPUT BRN WIRE BRN/WHT WIRE DASH FUSE BLOCK DATA CLASS II DK BLU WIRE ECM 1 FUSE ECM-B FUSE ECT SENS INPUT ELECTRONIC BRAKE CONTROL MODULE ENG 1 FUSE ENGINE COOLANT TEMP SENSOR (TOP RIGHT FRONT OF ENGINE) FRONT WHEEL LOCK FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT IN OFF, RUN OR START HOT IN RUN HOT IN RUN OR START IGNITION IN INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP MIL CONTROL ORG/ WIRE PCM GROUND PCS SOL HI OUT PCS SOL LO OUT PNK PNK WIRE 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 STOPLAMP SWITCH (ON BRAKE PEDAL BRACKET) TAN WIRE TAN/BLK WIRE TCC PWM SOL TCC PWM SOLENOID TCC SOL TCC 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 CIRCUIT PNK WIRE TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR VEHICLE SPEED SENSOR ADAPTOR VSS HI VSS LO WHT WIRE YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC SIGNAL IGNITION A/C COMP FUSE A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE CENTER) A/C COMPRESSOR CYCLING SWITCH (IN LOW PRESSURE LINE, ON ACCUMULATOR) A/C CTRL A/C ENABLE A/C HIGH PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) A/C LOW PRESSURE CUTOUT SWITCH (ON A/C COMPRESSOR) AIR TEMP DR SIGNAL MODE SIGNAL A/C SWITCH BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER FUSE 3 BLOWER MOTOR BLOWER RESISTOR (UNDER RIGHT SIDE OF DASH, ON HEATER HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT 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 HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER DASH ON TOP OF HEATER-A/C HOUSING) HOT AT ALL TIMES UNDERHOOD FUSE BLOCK HOT IN RUN HOT IN RUN OR START HTR A/C FUSE 12 IGN E FUSE LT BLU WIRE LT GRN WIRE OFF LO ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (BEHIND RIGHT SIDE OF DASH) PPL REAR DEFOGGER SYSTEM RECIRCULATION DOOR MOTOR (UNDER DASH ON HEATER- A/C HOUSING) RED WIRE TAN WIRE 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 BRAIDED GROUND STRAP CARGO DOOR JAMB SWITCH (SUBURBAN/ UTILITY ONLY) COURTESY LAMPS CTRL CTSY FUSE 3 DOME DEFEAT DOOR JAMB DOOR LOCK CONTROL MODULE (IN FRONT OF LEFT REAR WHEELWELL) FRONT DOME/ READING LAMPS GRY WIRE HEADLAMP, PANEL DIMMER SWITCH DOME LAMP DEFEAT HORN FUSE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK GAGES FUSE 4 I/P COMPART- MENT BOX LAMP I/P FUSE BLOCK IGN SW INTERIOR LAMP CONTROL MODULE (UNDER CENTER OF DASH) LAMP OUT LEFT FRONT DOOR COURTESY LAMP (IF EQUIPPED) LEFT FRONT DOOR JAMB SWITCH LEFT I/P COURTESY LAMP LEFT ILLUMINATED VANITY MIRROR LEFT REAR DOOR COURTESY LAMP (IF EQUIPPED) LEFT REAR DOOR JAMB SWITCH (IF EQUIPPED) MIRRORS SYSTEM NCA WIRE ORG/ WIRE OVERHEAD CONSOLE LAMPS CIRCUIT PNK PNK WIRE PNK WIRE PPL REAR DOME/ READING LAMPS (IF EQUIPPED) REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR COURTESY LAMP (IF EQUIPPED) RIGHT FRONT DOOR JAMB SWITCH RIGHT I/P COURTESY LAMP RIGHT ILLUMINATED VANITY MIRROR RIGHT REAR DOOR COURTESY LAMP (IF EQUIPPED) RIGHT REAR DOOR JAMB SWITCH (IF EQUIPPED) UNDERHOOD FUSE/RELAY CENTER UNDERHOOD LAMP W/ OVERHEAD CONSOLE W/ RKE W/O OVERHEAD CONSOLE W/O RKE W/O RKE W/ RKE WHT WIRE

BLK WIRE CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DOOR LOCK CONTROL MODULE (FRONT OF LEFT REAR WHEELHOUSE) DOOR LOCK RELAY (UNDER CENTER OF DASH) GROUND DOOR JAMB SW LOCK SIG UNLOCK SIG PPL GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK (LEFT SIDE OF DASH, LEFT FRONT DOOR JAMB SWITCH LEFT FRONT DOOR LOCK ACTUATOR LEFT FRONT DOOR LOCK SWITCH LEFT REAR DOOR JAMB SWITCH LEFT REAR DOOR LOCK ACTUATOR LOCK LT BLU WIRE ORG/ WIRE PPL PPL 4 DOOR PWR-ACCY CIRCUIT BREAKER REAR CARGO DOOR LOCK ACTUATOR (CARGO DOORS) REAR DOOR JAMB SWITCH REAR DOOR LOCK SWITCH (CARGO DOORS) RIGHT FRONT DOOR JAMB SWITCH RIGHT FRONT DOOR LOCK ACTUATOR RIGHT FRONT DOOR LOCK SWITCH RIGHT REAR CARGO DOOR CONTACTOR (RIGHT REAR DOOR JAMB) RIGHT REAR DOOR JAMB SWITCH RIGHT REAR DOOR LOCK ACTUATOR RR DOOR SW BATT (B+) TAN WIRE UNLOCK WHT 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

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