GMC Suburban K2500 (1985-1999) blk/wht Wiring diagrams

2-HI IND 4-HI IND 4-LO IND AUTO AUTOMATIC TRANSFER CASE CONTROL MODULE (BEHIND LEFT SIDE OF DASH) AUTOMATIC TRANSFER CASE SELECT SWITCH AWD IND AXLE CTRL AXLE SW B+ GND MOTOR FEED (CCW) MOTOR FEED (CW) BLK WIRE BLK/WHT WIRE BRAKE CONTROL BRN WIRE BRN/WHT WIRE DIESEL GASOLINE DK BLU/WHT WIRE DK GRN WIRE ENCODER LOGIC ENCODER MOTOR ASSEMBLY ENCODER SIG RTN FRONT AXLE ACTUATOR FRONT DRIVE SHAFT SPEED SENSOR REAR DRIVE SHAFT SPEED SENSOR FT SHAFT SPEED SIG FT SHAFT SPEED RTN FUSE 24 GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HEADLAMP/ DIMMER PANEL SWITCH PNK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START HOT WITH HEADLIGHT SW IN PARK OR HEAD I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) ILLUM FUSE 14 ILLUMINATION LAMP (2) IND INSTRUMENT CLUSTER LOW SIG LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE NEUTRAL IND ORG/ WIRE PARK PARK/ NEUTRAL POSITION SWITCH PNK WIRE PNP SW-PARK SIG IN PPL PPL/WHT WIRE PWR RED WIRE RED/WHT WIRE REF SERVICE SHIFT MOTOR SOLID STATE STOP LAMP SWITCH T CASE FUSE 2 TAN WIRE TAN/BLK WIRE VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) YEL WIRE YEL/BLK WIRE

2-HI IND 4-HI IND 4-LO IND AUTO AUTOMATIC TRANSFER CASE CONTROL MODULE (BEHIND LEFT SIDE OF DASH) AUTOMATIC TRANSFER CASE SELECT SWITCH AWD IND AXLE CTRL AXLE SW B+ GND MOTOR FEED (CCW) MOTOR FEED (CW) BLK WIRE BLK/WHT WIRE BRAKE CONTROL BRN WIRE BRN/WHT WIRE DIESEL GASOLINE DK BLU/WHT WIRE DK GRN WIRE ENCODER LOGIC ENCODER MOTOR ASSEMBLY ENCODER SIG RTN FRONT AXLE ACTUATOR FRONT DRIVE SHAFT SPEED SENSOR REAR DRIVE SHAFT SPEED SENSOR FT SHAFT SPEED SIG FT SHAFT SPEED RTN FUSE 24 GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HEADLAMP/ DIMMER PANEL SWITCH PNK WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START HOT WITH HEADLIGHT SW IN PARK OR HEAD I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) ILLUM FUSE 14 ILLUMINATION LAMP (2) IND INSTRUMENT CLUSTER LOW SIG LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE NEUTRAL IND ORG/ WIRE PARK PARK/ NEUTRAL POSITION SWITCH PNK WIRE PNP SW-PARK SIG IN PPL PPL/WHT WIRE PWR RED WIRE RED/WHT WIRE REF SERVICE SHIFT MOTOR SOLID STATE STOP LAMP SWITCH T CASE FUSE 2 TAN WIRE TAN/BLK WIRE VEHICLE CONTROL MODULE (GASOLINE) (LEFT SIDE OF ENGINE COMPT) YEL WIRE YEL/BLK WIRE

AUXILIARY BATTERY RELAY BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FRONT AXLE ACTUATOR FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HARN) HOT IN PARK OR HEAD HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR LT BLU WIRE M/T A/T POWERTRAIN CONTROL MODULE (BEHIND RIGHT RED WIRE SIDE OF DASH) TIMER LOGIC, RELAY MODULE (RIGHT SIDE OF FIREWALL) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT)

AUXILIARY BATTERY RELAY BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FRONT AXLE ACTUATOR FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HARN) HOT IN PARK OR HEAD HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR LT BLU WIRE M/T A/T POWERTRAIN CONTROL MODULE (BEHIND RIGHT RED WIRE SIDE OF DASH) TIMER LOGIC, RELAY MODULE (RIGHT SIDE OF FIREWALL) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT)

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID 29 30 VSS LO (GROUND) VSS HI (SIGNAL) ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CRUISE CONTROL DK BLU WIRE ECM 1 FUSE ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE ENGINE CONTROLS ENGINE COOLANT TEMPERATURE SENSOR (TOP RIGHT FRONT OF ENGINE) FLUID TEMP SENSOR FRONT WHEEL LOCK FUEL INJECTORS, IGNITION CONTROL MOUDULE, IGNITION COIL FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GRY WIRE GRY/BLK WIRE HI LO HOT AT ALL TIMES HOT IN HOT IN OFF, RUN OR START HOT IN RUN OR START HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DSAH) GAUGES FUSE 4 I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INLINE GENDER ADAPTOR INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP ORG/ WIRE PNK PNK WIRE PNK WIRE PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL/WHT WIRE PRESS CTRL SOLENOID RED WIRE RED/BLK WIRE REV, LO RUN WIRE TAN WIRE TCC PWM SOLENOID TCC/ABS/ CRUISE SWITCH THROTTLE POSITION SENSOR (MOUNTED TO SIDE OF THROTTLE BODY) TRANS FUSE 20 TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSFER CASE CIRCUIT TRANSFER CASE, AXLE SWITCHES UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT SIDE OF YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID A/T ISS SENSOR VSS IN SENSOR GROUND SENSOR GROUND APP 1 SIGNAL IN ACCELERATOR PEDAL POSITION MODULE (PART OF ACCELERATOR PEDAL) APP 3 SIGNAL IN SENSOR GROUND A/T ISS SENS LO AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE PPL ENGINE CONTROLS SYSTEM ENGINE SHUTOFF SOLENOID, FUEL SOLENOID EXTERIOR LIGHTS FUEL PUMP, OIL PRESS SWITCH/ SENDER, FUEL PUMP RELAY GAUGES FUSE 4 GRY WIRE GRY/BLK WIRE HI LO HOT AT ALL TIMES HOT IN HOT IN RUN OR START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INLINE GENDER ADAPTOR INSTRUMENT CLUSTER LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE MALFUNCTION INDICATOR LAMP ORG/ WIRE PNK PPL WIRE PNK WIRE POWERTRAIN CONTROL MODULE (RIGHT SIDE OF DASH NEAR BLOWER MOTOR) PPL PPL DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) PPL PNK PNK WIRE PPL PRESS CTRL SOLENOID PPL/WHT WIRE RED WIRE RED/BLK WIRE RUN WIRE STOP/HAZ FUSE 1 TAN WIRE TAN/WHT WIRE TCC PWM SOLENOID TRANS FLUID TEMP SENSOR TRANS FUSE 20 TRANS RANGE PNK PNK REV, LO WIRE TRANS RANGE PRESSURE SWITCH ASSEMBLY TRANSFER CASE CIRCUIT TRANSFER CASE CIRCUIT PNK WIRE TURN/ HAZARD SWITCH, CHIME MODULE VEHICLE SPEED SENSOR (LEFT SIDE OF VEHICLE SPEED SENSOR BUFFER (RIGHT SIDE OF DASH) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC CTRL IGNITION 1995 VFTC A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH DIODE A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C COMPRESSOR CYCLING SWITCH (ON TOP OF ACCUMULATOR) A/C COMPRESSOR HIGH PRESSURE CUTOUT SWITCH (REAR OF THE A/C COMPRESSOR) A/C COMPRESSOR LOW PRESSURE CUTOUT SWITCH (ON TOP OF A/C COMPRESSOR) A/C FUSE AIR TEMP DR SENSOR MODE SIGNAL A/C REQUEST AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (IN UNDERHOOD FUSE/RELAY CENTER) BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLK/WHT WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH OFF LO BRN WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C- HEATER BLOWER HOUSING) HOT AT ALL TIMES HOT IN RUN HOT IN RUN I/P IGN E FUSE FUSE BLOCK HTR A/C FUSE 12 HVAC CONTROL MODULE LT BLU WIRE LT GRN WIRE ORG/ WIRE PNK WIRE PPL REAR DEFOGGER SYSTEM RECIRCULATION DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) RED WIRE RELAY CONTROL SWITCH SIGNAL TAN WIRE UNDERHOOD FUSE BLOCK VEHICLE CONTROL MODULE (ON LEFT SIDE OF ENGINE COMPARTMENT) 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 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE RECIRC CTRL IGNITION 1995 VFTC A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH DIODE A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE BOX) A/C COMPRESSOR CYCLING SWITCH (ON TOP OF ACCUMULATOR) A/C COMPRESSOR HIGH PRESSURE CUTOUT SWITCH (REAR OF THE A/C COMPRESSOR) A/C COMPRESSOR LOW PRESSURE CUTOUT SWITCH (ON TOP OF A/C COMPRESSOR) A/C FUSE A/C REQUEST AIR TEMP DR SENSOR MODE SIGNAL A/C REQUEST AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (IN UNDERHOOD FUSE/RELAY CENTER) BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLK/WHT WIRE BLOWER FUSE 3 BLOWER MOTOR (UNDER RIGHT SIDE OF DASH) BLOWER RESISTOR (ON BLOWER MOTOR HOUSING) BLOWER SWITCH OFF LO BRN WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE GRY WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C- HEATER BLOWER HOUSING) HOT AT ALL TIMES HOT IN RUN HOT IN RUN I/P IGN E FUSE FUSE BLOCK HTR A/C FUSE 12 HVAC CONTROL MODULE LT BLU WIRE LT GRN WIRE ORG/ WIRE PNK WIRE PPL REAR DEFOGGER SYSTEM RECIRCULATION DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) RED WIRE RELAY CONTROL SWITCH SIGNAL TAN WIRE UNDERHOOD FUSE BLOCK VEHICLE CONTROL MODULE (ENGINE COMPARTMENT NEAR EBCM) WHT WIRE YEL 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