Chevrolet Cab & Chassis C3500 (1989-2000) underhood fuse-relay center Wiring diagrams

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

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

AUDIO ALARM MODULE AUDIO AMPLIFIER AUTOMATIC AUTOMATIC TRANSFER CASE AUTOMATIC TRANSFER CASE CONTROL MODULE BASE AUX/PWR FUSE 7 BASE CARGO DOOR UPPER LEVLE BATTERY FUSE 7 BLK WIRE CIG LTR FUSE 13 CIGAR LIGHTER COLUMN HARNESS BREAKOUT) CONVENIENCE CENTER DATA LINK CONNECTOR DOOR REAR LIFTGATE LOCK DOOR RELEASE CONTROL LOCK RELAY MODULE SWITCH ELECTRIC FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 1 OF 6) I/P CLUSTER BREAKOUT) I/P FUSE BLOCK INSTRUMENT CLUSTER LEFT FRONT DOOR LOCK SWITCH LIFTGATE RELEASE SWITCH NON- BASE ORG/ WIRE OTHERS PICKUP POLICE PACKAGE UPPER LEVEL POWER OUTLET BREAKOUT) PWR-ACCY CIRCUIT BREAKER (REGULAR CAB/EXTENDED CAB) RADIO RADIO BATT FUSE 19 REAR AUXILIARY POWER CONNECTOR REAR CONSOLE AUXILIARY POWER CONNECTOR RED WIRE REMOTE CONTROL DOOR LOCK RECEIVER REMOTE RIGHT FRONT CONTROL DOOR LOCK DOOR LOCK SWITCH RECEIVER RIGHT FRONT LEFT FRONT POWER POWER LUMBAR LUMBAR SEAT SWITCH SEAT SWITCH RIGHT LUMBAR POWER SEAT RIGHT LUMBAR POWER SEAT SWITCH RIGHT POWER SEAT ADJUSTER SWITCH SEAT LUMBAR SWITCH BREAKOUT) STEERING COLUMN HARNESS BREAKOUT) STOP LAMP SWITCH STOP/HAZ FUSE 1 SUBURBAN/ UTILITY SWITCH T CASE FUSE 2 TO SEATS FUSE (DIAGRAM 3 OF 6) TRANSFER CASE CONTROL MODULE TURN/ HAZARD SWITCH UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL VEHICLE INTERFACE UNIT W/ RKE W/BENCH SEAT W/O RKE

A/T M/T AIR BAG FUSE 10 BODY CONTROL MODULE BODY REAR CONTROL STEREO MODULE CONTROLLER BRN WIRE CLUTCH PEDAL PARK/NEUTRAL POSITION POSITION SWITCH SWITCH COLUMN HARN BREAKOUT) PNK WIRE CONVENIENCE CENTER CRANK FUSE 8 DAYTIME RUNNING LAMPS MODULE DK BLU WIRE ELECTROCHROMIC REARVIEW MIRROR W/ COMPASS FROM CONVENIENCE CENTER BREAKOUT) FROM IGNITION SWITCH (DIAGRAM 3 OF 6) FROM UNDERHOOD FUSE-RELAY CENTER GAS DIESEL GAUGES FUSE 4 HEADLAMP, PANEL DIMMER SWITCH I/P FUSE BLOCK IGN A FUSE 6 IGN B FUSE 5 IGNITION SWITCH INFLATABLE RESTRAINT I/P MODULE SWITCH (PICKUP) INFLATABLE RESTRAINT SENSING AND DIAGNOSTIC MODULE INTERIOR LAMP CONTROL MODULE OR REMOTE CONTROL DOOR LOCK RECEIVER LOCK OFF M/T M/T A/T ORG/ WIRE OTHERS PNK WIRE POWER WINDOW MASTER SWITCH PPL PWR WDO CIRCUIT BREAKER RADIO RADIO FUSE 17 REAR WINDOW LOCKOUT SWITCH (4-DR) RED WIRE RR WIPER FUSE 23 TRANS FUSE 20 WIPER FUSE 11 RUN WIRE STARTER RELAY TO SEATS FUSE (DIAGRAM 5 OF 6) TO UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 4 OF 6) PNK WIRE TRANSFER CASE SELECT SWITCH TURN B/U FUSE 16 UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL UPPER LEVEL (FLOOR CONSOLE HARN, 33 CM HEATED SEAT SWITCH BREAKOUT) VEHICLE RIGHT FRONT INTERFACE POWER UNIT WINDOW SWITCH (2 DR, UTILITY) VEHICLE SPEED SENSOR BUFFER (DIESEL) W/O RKE W/ RKE WHT WIRE WINDSHIELD WIPER INSTRUMENT MOTOR CLUSTER MODULE YEL WIRE

5.0L, 5.7L 6.5L 7.4L 7.4L W/ CALIFORNIA EMISSIONS OTHERS A/C CLUTCH RELAY A/C COMPRESSOR CLUTCH RELAY AIR INTAKE RECIRCULATION RELAY (5.7L) AIR RELAY BALANCE MODULE BREAKOUT) CRANK- SHAFT POSITION SENSOR DIESEL ECM 1 FUSE EGR LINEAR PWM VALVE SOLENOID EGR SOLENOID ENG 1 FUSE ENGINE SHUTOFF SOLENOID EVAPORATIVE EMISSIONS CANISTER PURGE SOLENOID VALVE FROM EBCM BREAKOUT) FROM SPLICE FUEL FUEL FUEL INJECTOR INJECTOR INJECTOR FUEL FUEL INJECTOR INJECTOR FUEL FUEL PUMP PUMP BALANCE BALANCE MODULE RELAY FUEL HEATER FUEL IGNITION CRANK- INJECTOR CONTROL SHAFT MODULE POSITION SENSOR FUEL INJECTOR FUEL SOLENOID DRIVER GASOLINE GLOW PLUG RELAY IGN E FUSE IGNITION COIL IGNITION CONTROL MODULE MASS AIRFLOW EVAPORATIVE SENSOR EMISSION CANISTER VENT MASS EGR AIR FLOW BOOST SENSOR SOLENOID PNK (ENG HARN, 26 CM FROM EBCM BREAKOUT) WIRE PNK WIRE POWERTRAIN CONTROL MODULE UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE WATER IN-FUEL SENSOR

AUTOMATIC TRANSFER CASE CONTROL MODULE AUTOMATIC TRANSFER CASE ONLY AUTOMATIC TRANSFER CASE SELECT SWITCH AUXILIARY AUXILIARY TEMPERATURE HIGH BLOWER DOOR MOTOR MOTOR RELAY 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) AUXILIARY MEDIUM BLOWER MOTOR RELAY BLK WIRE BLK/RED WIRE BLU WIRE BRAKE FUSE 18 BREAKOUT) BRN WIRE COLUMN HARNESS BREAKOUT) CONVENIENCE CENTER CROSSBODY HARN, 20 CM FROM SDM BREAKOUT) CRUISE CONTROL MODULE (GAS ONLY) CRUISE CONTROL SWITCH CRUISE FUSE 6 ELECTRONIC BRAKE CONTROL MODULE FROM BREAKOUT TO GROUND AT LEFT SIDE FRAME RAIL, NEAR CROSSMEMBER) FROM IGNITION SWITCH (DIAGRAM 3 OF 6) FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 1 OF 6) FROM UNDERHOOD FUSE-RELAY CENTER (DIAGRAM 3 OF 6) FRONT AXLE ACTUATOR FRONT HEATED SEATS FUSE FUSE 24 FUSIBLE LINK GAS, BASE MODELS DIESEL GAS, OTHERS MODELS HTR A/C FUSE 12 HVAC CONTROL MODULE I/P FUSE BLOCK LEFT FRONT FENDER) LEFT FRONT HEATED SEAT MODULE LEFT REAR HEATED SEAT MODULE LEFT REAR HEATED SEAT SWITCH MODE DOOR MOTOR MOTOR RELAYS) ORG/ WIRE REAR HEATED SEATS FUSE REAR HEATER REAR HEATER W/ W/ REAR CARGO LIFT- HEATER DOORS GATE ONLY RECIRCULATION TEMPERATURE DOOR DOOR MOTOR MOTOR RED WIRE RESTRAINT SWITCH BREAKOUT) RIGHT FRONT HEATED SEAT MODULE RR HVAC FUSE 5 SEATS FUSE STOP LAMP SWITCH SUBURBAN, UTILITY ONLY TRANSFER SPARE CASE POWER SWITCH SOURCE UNDERHOOD FUSE-RELAY CENTER UPPER LEVEL VEHICLE CONTROL MODULE (GAS ONLY) W/ REAR DEFROST

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 BRAKE CONTROL MODULE (EBCM) (ON LEFT SIDE OF ENGINE COMPT) 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 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 INPUT BRAKE SW INPUT 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 INPUT SERIAL DATA SIG MANUAL OR SELECTABLE ORG/ WIRE PNK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 SENSOR INPUT STOPLAMP/ CLUTCH SWITCH INPUT VCM SIG 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) TRANSMISSIONS SYSTEM UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE