GMC Pickup K2500 (1985-2000) blk Wiring diagrams

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 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 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 CONVENIENCE CENTER (UNDER LEFT SIDE OF I/P) FUSE BLOCK (LOWER LEFT SIDE OF I/P) GRY WIRE HOT AT ALL TIMES LEFT FRONT DOOR LOCK ACTUATOR SOLID STATE LEFT FRONT DOOR LOCK SWITCH LOCK LT BLU WIRE ORG/ WIRE PWR ACC CIRCUIT BREAKER RIGHT FRONT DOOR LOCK ACTUATOR SOLID STATE RIGHT FRONT DOOR LOCK SWITCH TAN WIRE UNLOCK WHT WIRE

260 (CROSS BODY HARNESS, 4 DOOR 4-DOOR 2-DOOR 640 (OR 540) 1576 (OR 56) 294 39 157 1455 150 195 156 BLK (OR BLK/WHT) WIRE BLK WIRE BLK/WHT WIRE CARGO DOOR JAMB SWITCH CARGO DOOR LOCK SWITCH (W/ CARGO DOORS) CIG LTR FUSE 13 CONVENIENCE CENTER (LEFT SIDE OF DASH) DATA LINK INTERIOR CONNECTOR LAMPS (UNDER LEFT SYSTEM SIDE OF DASH) DOOR LOCK CONTROL MODULE (FRONT OF LEFT REAR WHEELWELL) DOOR LOCK RELAY (UNDER CENTER OF DASH, NEAR REMOTE CONTROL DOOR LOCK RECEIVER) GAUGES FUSE 4 GROUND DOOR JAMB SW LOCK SIG UNLOCK SIG PPL GRY WIRE HORNS SYSTEM HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START 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 LUXURY ORG/ WIRE ORG/BLK WIRE PNK WIRE PPL PWR-ACCY CIRCUIT BREAKER REAR CARGO DOOR LOCK ACTUATOR (CARGO DOORS) REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) 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+) SEAT BELT SWITCH BREAKOUT) SUBURBAN/ UTILITY TAN WIRE TRUNK, TAIL- GATE, FUEL DOORS SYSTEM UNLOCK UTILITY W/ REAR CARGO DOORS UTILITY W/ REAR LIFTGATE W/ CARGO DOORS W/ LIFTGATE W/ CARGO DOORS W/O POWER WINDOWS W/ POWER WINDOWS WHT WIRE

A/C COMP MINI FUSE A/C MAXI FUSE 3 MAXI FUSE 4 A/C RELAY AUX FAN RELAY MINI FUSE AUXILIARY COOLING FAN RELAY BLK WIRE BLK/RED WIRE BLOWER LOW RELAY BLOWER RELAY BLU WIRE BRAKE LAMP RELAY UNDERHOOD FUSE-RELAY CENTER CARGO LAMP SWITCH (PICK-UP ONLY) CONVENIENCE CENTER CONVENIENCE CONVENIENCE CENTER CENTER CTSY FUSE 3 DAYTIME LEFT RUNNING COURTESY LAMPS LAMP RELAY DIESEL DIESEL EXCEPT DIESEL DIESEL GASOLINE DIODE DRL/FOG FUSE 15 ECM-B MINI FUSE ELECTRONIC CONVENIENCE CENTER BRAKE CONTROL MODULE FRONT DOME/ READING LAMPS FUEL PUMP OIL PRESSURE SWITCH AND SENDER FUEL PUMP RELAY UNDERHOOD FUSE-RELAY CENTER FUSIBLE LINK (10 GA-RUST) GAS GENERATOR HEADLAMP AND PANEL DIMMER SWITCH HEATER AND A/C CONTROL SWITCH HORN MINI FUSE HORN RELAY I/P COMPARTMENT LAMP I/P FUSE BLOCK INTERIOR LAMP CONTROL MODULE LEFT BATTERY (DIESEL) LEFT ILLUMINATED VANITY MIRROR MAXI FUSE MAXI FUSE 2 MAXI FUSE 8 ORG/ WIRE PK LPS FUSE 9 POWERTRAIN CONTROL MODULE (DIESEL) REAR DOME READING LAMPS RED WIRE REMOTE BATTERY STUD RIGHT BATTERY RIGHT COURTESY LAMP RIGHT FRONT DOOR COURTESY LAMP RIGHT REAR DOOR COURTESY LAMP RR-DEFOG MINI FUSE STARTER MOTOR SOLENOID TO FUSIBLE LINK (DIAGRAM 4 OF 4) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 2 OF 4) UNDERHOOD FUSE-RELAY CENTER UNDERHOOD LAMP UNDERHOOD REEL LAMP VEHICLE CONTROL MODULE (GASOLINE) YEL WIRE

AUDIO ALARM MODULE AUX/PWR FUSE 7 AUXILIARY POWER CONNECTOR BLK WIRE BRN WIRE CIG LTR FUSE 13 CIGAR LIGHTER CONVENIENCE CENTER CRANK FUSE 8 DATA LINK CONNECTOR DOOR REMOTE CONTROL LOCK DOOR LOCK RELAY RECEIVER FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 1 OF 4) I/P FUSE BLOCK IGNITION SWITCH INSTRUMENT CLUSTER LEFT FRONT DOOR LOCK SWITCH LEFT FRONT RIGHT FRONT POWER DOOR LOCK DOOR LOCK AMPLIFIER SWITCH SWITCH RELAY LEFT POWER SEAT LOCK LOCK OFF OFF LOCK OFF M/T A/T MAXI FUSE 5 MAXI FUSE 6 MAXI FUSE 7 NCA WIRE ORG/ WIRE PNK WIRE POWER WDO CIRCUIT BREAKER PPL PWR-ACCY CIRCUIT BREAKER RADIO RADIO BATT FUSE 19 RADIO FUSE 17 REAR DOOR DOOR LOCK LOCK SWITCH CONTROL MODULE REAR WINDOW LOCKOUT SWITCH (4-DR) RED WIRE REMOTE CONTROL DOOR LOCK RECEIVER RIGHT FRONT DOOR LOCK SWITCH RIGHT FRONT POWER LUMBAR SEAT SWITCH RIGHT FRONT POWER POWER WINDOW WINDOW MASTER SWITCH SWITCH (2 DR, UTILITY) RR WIPER FUSE 23 WIPER FUSE 11 RUN WIRE STARTER RELAY UNDERHOOD FUSE-RELAY CENTER STOP/HAZ FUSE 1 SUBURBAN ONLY SUBURBAN/ UTILITY PICKUP T CASE FUSE 2 TCC/STOPLAMP SWITCH TO I/P FUSE BLOCK (DIAGRAM 4 OF 4) TO SECURITY/ STRG FUSE 21 (DIAGRAM 4 OF 4) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 3 OF 4) TRANS FUSE 20 TRANS- MISSION TRANSFER CASE CONTROL MODULE TURN/ HAZARD SWITCH UNDERHOOD FUSE-RELAY CENTER W/BENCH SEAT W/O BENCH SEAT WHT WIRE WINDSHIELD RADIO WIPER MOTOR MODULE YEL WIRE

4.3L PNK WIRE 7.4L 6.5L 7.4L W/ CALIFORNIA EMISSIONS OTHERS A/C CLUTCH RELAY A/T M/T AIR BAG FUSE 10 AIR INJECTION REACTION SECONDARY RELAY BACKUP LAMP SWITCH BLK WIRE CAMSHAFT EXHAUST POSITION GAS SENSOR RECIRCULATION VALVE CONVENIENCE CENTER DAYTIME AUDIO RUNNING ALARM MODULE LAMPS RELAY DIESEL ONLY PNK WIRE EGR SOLENOID ELECTROCHROMATIC MIRROR W/ COMPASS ELECTRONIC INJECTION PUMP ENG-1 MINI FUSE EVAPORATIVE EMISSION CANISTER VENT EVAPORATIVE FUEL EMISSIONS PUMP CANISTER PURGE BALANCE SOLENOID VALVE RELAY FROM IGNITION SWITCH (DIAGRAM 2 OF 4) FUEL EGR GLOW WATER-IN- HEATER VENT PLUG FUEL SOLENOID CONTROL SENSOR MODULE FUEL FUEL FUEL INJECTOR INJECTOR INJECTOR FUEL FUEL INJECTOR INJECTOR FUEL INJECTOR FUEL PUMP BALANCE MODULE FUEL SOL MINI FUSE ECM 1 MINI FUSE FUEL TANK DAYTIME SENDER RUNNING I/P MODULE LAMPS CLUSTER MODULE (4.3L) GASOLINE DIESEL 5.0L, 5.7L 4.3L GAUGES FUSE 4 HEATED HEATED MASS OXYGEN OXYGEN AIRFLOW SENSOR 1 SENSOR 2 SENSOR HEATED HEATED OXYGEN OXYGEN SENSOR 4 SENSOR 3 I/P FUSE BLOCK IGN E MINI FUSE IGNITION CRANK- CONTROL SHAFT MODULE POSITION SENSOR IGNITION CRANK- FUEL CONTROL SHAFT INJECTOR MODULE POSITION SENSOR INFLATABLE RESTRAINT I/P MODULE ENABLE SWITCH INFLATABLE RESTRAINT SENSING AND DIAGNOSTIC MODULE M/T MASS AIR FLOW SENSOR NCA WIRE PNK WIRE POWER STEERING CONTROL MODULE POWERTRAIN CONTROL MODULE TRANSFER CASE CONTROL MODULE TURN B/U FUSE 16 TURN SIGNAL SWITCH UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE VEHICLE IGNITION CONTROL COIL MODULE WASTEGATE SOLENOID YEL WIRE

AUXILIARY BATTERY AUXILIARY BATTERY RELAY (LEFT REAR OF ENGINE COMPT) AUXILIARY HEATER AND A/C CONTROL LOGIC MODULE AUXILIARY HEATER AND A/C CONTROL MODULE (FRONT) AUXILIARY HEATER AND A/C CONTROL MODULE (REAR) BLK WIRE BLK/RED WIRE BLU WIRE BRAKE FUSE 18 BRN WIRE CONVENIENCE CENTER CRUISE CONTROL MODULE CRUISE CONTROL SWITCH CRUISE FUSE 6 DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE EXCEPT DIESEL DIESEL FROM IGNITION SWITCH (DIAGRAM 2 OF 4) FROM STOP/HAZ FUSE 1 (DIAGRAM 2 OF 4) FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 1 OF 4) FRONT MODE DOOR MOTOR FRONT TEMPERATURE DOOR MOTOR FUSE 24 FUSIBLE LINK GRY WIRE HEATER AND A/C CONTROL MODULE HEATER AND A/C CONTROL SWITCH HTR A/C FUSE 12 I/P FUSE BLOCK ILLUM FUSE 14 INTERIOR LIGHTS SYSTEM (HEADLAMP AND PANEL LAMP DIMMER) LEFT FRONT FENDER) ORG/ WIRE POWER STEERING CONTROL MODULE REAR AUXILIARY TEMPERATURE DOOR MOTOR REAR HIGH BLOWER RELAY REAR LOW BLOWER RELAY REAR REAR MEDIUM AUXILIARY BLOWER MODE DOOR RELAY MOTOR RECIRCULATION DOOR MOTOR RR HVAC FUSE 5 SECURITY/ STRG FUSE 21 TCC/ STOPLAMP SWITCH TRANSFER SPARE CASE POWER SELECT SOURCE SWITCH VEHICLE CONTROL MODULE

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 5 CM FROM TRANSFER CASE RELAY BREAKOUT FROM AXLE SWITCH) 79 CM FROM ENGINE HARNESS BREAK-OUT) 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 FRONT AXLE SWITCH (RIGHT REAR OF FRONT DRIVE AXLE) FUSE 24 GASOLINE GAUGES FUSE 4 GROUND GROUND GROUND BATTERY IN BATTERY IN PNP SWITCH OUT 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) ILLUMINATION LAMP LT BLU WIRE LT GRN WIRE ORG (OR LT GRN/BLK) WIRE ORG/ WIRE PARK/NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PNK IGNITION IN ENCODER GROUND GROUND 2 HI INDIC CTRL 4 HI INDIC CTRL WIRE PNK WIRE POWERTRAIN CONTROL MODULE (DIESEL) PPL/WHT WIRE REAR LIFTGATE WINDOW RELEASE CIRCUIT RED WIRE RED/WHT WIRE SPARE POWER SOURCE AUXILIARY BATTERY RELAY SPARE POWER SOURCE 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 (LEFT SIDE CENTER OF TRANSFER CASE) TRANSFER CASE ENCODER MOTOR (LEFT SIDE OF TRANSFER CASE) TRANSFER CASE RELAY (1-TON VEHICLES ONLY) (RIGHT SIDE OF FIREWALL) TRANSFER CASE SELECT SWITCH TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) TRANSFER CASE SYNCHRONIZER (TOP OF TRANSFER CASE) TURN B/U FUSE 16 TURN SIGNAL SWITCH WHT WIRE YEL WIRE YEL/BLK WIRE