Chevrolet Pickup C2500 (1988-2000) underhood fuse-relay center Wiring diagrams

A/C COMP FUSE AUX FAN CTRL AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (IN UNDERHOOD FUSE/RELAY CENTER) BLK WIRE DK BLU WIRE DK GRN WIRE FAN REQ HEATER AND A/C CONTROL MODULE HOT AT ALL TIMES HOT IN RUN OR START ORG/ WIRE RECIRCULATION DOOR MOTOR (ON A/C- HEATER HOUSING) RED WIRE RELAY CTRL UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (LEFT REAR OF ENGINE COMPT)

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL 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 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 FUSE 3 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 MODE DOOR MOTOR (ON FRONT A/C-HEATER HOUSING) FUSE BLOCK GRY WIRE GRY/BLK WIRE HIGH BLOWER RELAY (ON TOP OF FRONT A/C-HEATER HOUSING) HOT AT ALL TIMES HOT AT ALL TIMES UNDERHOOD FUSE-RELAY CENTER 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-RELAY CENTER VALVE CTRL AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) WATER VALVE (SUBURBAN, UTILITY, CREW CAB ONLY) (RIGHT CENTER OF INTAKE AREA) WHT WIRE YEL WIRE

A/C COMP FUSE AUX FAN CTRL AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (IN UNDERHOOD FUSE/RELAY CENTER) BLK WIRE DK BLU WIRE DK GRN WIRE FAN REQ HEATER AND A/C CONTROL MODULE HOT AT ALL TIMES HOT IN RUN OR START ORG/ WIRE RECIRCULATION DOOR MOTOR (ON A/C- HEATER HOUSING) RED WIRE RELAY CTRL UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (LEFT REAR OF ENGINE COMPT)

A/C COMP FUSE AUX FAN CTRL AUX FAN FUSE AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (IN UNDERHOOD FUSE/RELAY CENTER) BLK WIRE DK BLU WIRE DK GRN WIRE FAN REQ HEATER AND A/C CONTROL MODULE HOT AT ALL TIMES HOT IN RUN OR START ORG/ WIRE RECIRCULATION DOOR MOTOR (ON A/C- HEATER HOUSING) RED WIRE RELAY CTRL UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (LEFT REAR OF ENGINE COMPT)

4.3L A/C COMPRESSOR CLUTCH A/C COMPRESSOR CYCLING SWITCH A/C HIGH PRESSURE (NOT CUTOUT USED) SWITCH AIR REACTION INJECTION (SECONDARY) WATER PUMP VALVE (7.4L ONLY) BALANCE FUEL FUEL PUMP GAGE BALANCE SENDER MODULE BLK WIRE BLK/WHT WIRE BLOWER MOTOR BRAKE PRESSURE WARNING SWITCH CRUISE INSTRUMENT CONTROL CLUSTER MODULE DATA LINK CONNECTOR DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE EVAPORATIVE EMISSIONS PURGE VACUUM SOLENOID SWITCH EXCEPT 4.3L FRONT AXLE ACTUATOR FRONT MODE DOOR MOTOR FRONT TEMPERATURE DOOR MOTOR FUEL PUMP AND SENDER GASOLINE HEATED OXYGEN SENSOR BANK 1 SENSOR 1 HEATED OXYGEN SENSOR BANK 1 SENSOR 2 HEATED OXYGEN SENSOR BANK 2 SENSOR 1 HEATED OXYGEN SENSOR BANK 2 SENSOR 2 HIGH A/C PRESSURE CUTOUT SWITCH HIGH BLOWER MOTOR RELAY IGNITION COIL MODULE MASS AIRFLOW SENSOR PARK/ NEUTRAL POSITION SWITCH POWER STEERING CONTROL MODULE RECIRCULATION DOOR MOTOR STARTER RELAY STOPLAMP RELAY TRANSFER CASE RELAY TRANSFER CASE RELAY BREAKOUT) UNDER- HOOD LAMP UNDERHOOD FUSE- RELAY CENTER A/C COMPRESSOR CLUTCH RELAY UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE VEHICLE UNDER- SPEED HOOD SENSOR REEL (BLUNT CUT) LAMP W/ DUAL TANKS W/O DUAL TANKS (EXCEPT 4.3L) UNDERHOOD FUSE- RELAY CENTER FUEL PUMP RELAY

A/C COMPRESSOR CLUTCH A/C LOW PRESSURE SWITCH BLK WIRE BLOWER MOTOR BRAKE PRESSURE WARNING SWITCH DIESEL DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE FRONT AXLE ACTUATOR FRONT MODE DOOR MOTOR FRONT TEMPERATURE DOOR MOTOR HIGH BLOWER MOTOR RELAY LOW GLOW COOLANT PLUG LEVEL RELAY SENSOR PARK/ NEUTRAL POSITION SWITCH RECIRCULATION DOOR MOTOR STOPLAMP STARTER RELAY RELAY TRANSFER CASE RELAY TRANSFER CASE RELAY BREAKOUT) UNDER- HOOD LAMP UNDER- HOOD REEL LAMP UNDERHOOD FUSE- RELAY CENTER A/C COMPRESSOR CLUTCH RELAY UNDERHOOD FUSE-RELAY CENTER WATER-IN- FUEL FUEL HEATER SENSOR

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 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 RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER 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 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 RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL WIRE

7.4L A/C COMP FUSE A/C COMPRESSOR CLUTCH RELAY ABS FUSE 4 AUX FAN FUSE RR DEFOG FUSE AUX PWR AUTO HEADLAP FUSE 22 AUXILIARY AUXILIARY MEDIUM HIGH BLOWER BLOWER MOTOR MOTOR RELAY RELAY AUXILIARY COOLING FAN RELAY AUXILIARY ROOF LAMP RELAY AUXILIARY ROOF LAMP SWITCH BLK WIRE BLOWER FUSE 3 BLU WIRE BRAKE CONTROL MODULE BREAKOUT) BRAKE LAMP RELAY UNDERHOOD FUSE-RELAY CENTER BREAKOUT GASOLINE-ENG HARN, BREAKOUT) CAMP/TRAIL FUSE CARGO LAMP SWITCH CONN CONVENIENCE CENTER CTSY FUSE 3 DIODE DRL/FOG FUSE 15 DUAL BATTERY ECM-B FUSE ELECTRONIC BRAKE CONTROL MODULE EVO/ PASSLOCK MODULE FROM LT GRN 6-PIN WIRE FRONT POWER REAR DOME OUTSIDE DOME REARVIEW LAMPS LAMPS MIRROR SWITCH FUEL PUMP OIL PRESSURE SWITCH AND SENDER FUEL PUMP RELAY UNDERHOOD FUSE-RELAY CENTER FUSIBLE LINK (10 GA-RUST) GARAGE OVERHEAD DOOR CONSOLE OPENER READING LAMPS GENERATOR (BASE) GENERATOR (UPLEVEL) HEADLAMP HEADLAMP AND PANEL DIMMER SWITCH HEADLAMP CONTROL MODULE HEATER AND A/C CONTROL SWITCH HEATER MIRROR RELAY HIGH AUXILIARY BLOWER LOW MOTOR BLOWER RELAY MOTOR RELAY HORN FUSE HORN RELAY UNDERHOOD LAMP UNDERHOOD FUSE- RELAY CENTER HTD MIR FUSE I/P COMPARTMENT BOX LAMP I/P FUSE BLOCK INFLATABLE RESTRAINT SWITCH BREAKOUT) INSTRUMENT CLUSTER (POLICE RIGHT PACKAGE) VANITY MIRROR LEFT BATTERY (DIESEL) LEFT COURTESY LAMP LEFT VANITY MIRROR MEGA FUSE BLOCK NCA WIRE OR BLK 8-PIN IN-LINE WIRE ORG/ WIRE OVERHEAD FRONT INTERIOR CONSOLE DOME LAMP CONTROL READING LAMP MODULE LAMPS PANEL DIMMER SWITCH PICKUP ONLY PK LPS FUSE 9 POWERTRAIN CONTROL MODULE (DIESEL) RADIO BATT FUSE 19 AUX FUSE 22 RED WIRE REMOTE BATTERY STUD RIGHT BATTERY RIGHT COURTESY LAMP SECURITY/ STRG FUSE 21 SEO FUSE SINGLE BATTERY (BASE) SINGLE BATTERY (UPLEVEL) SPARE POWER SOURCE SPOTLAMP (POLICE PACKAGE) STARTER MOTOR SOLENOID STOP FUSE 2 LIGHTING FUSE 8 TO FUSIBLE LINK (DIAGRAM 5 OF 6) TO MEGAFUSE (DIAGRAM 6 OF 6) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 2 OF 6) UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL VEHICLE CONTROL MODULE (GASOLINE) W/O RKE YEL WIRE

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