Jonathan Yarden Mar 25, 2021 · 5 min. read
In this article you will find a description of fuses and relays Chevrolet,
with photos of block diagrams and their locations.
Highlighted the cigarette lighter fuse (as the most popular thing people look for).
Get tips on blown fuses, replacing a fuse, and more.
Year of production: 2003
Instrument panel fuse block
The fuse block access door is on the driver’s side edge of the instrument panel.
| Fuses | Usage |
| RR Wiper | Rear Window Wiper Switch |
| SEO ACCY | Special Equipment Option Accessory |
| WS WPR | Windshield Wipers |
| TBC ACCY | Truck Body Controller Accessory |
| IGN 3 | Ignition, Heated Seats |
| 4WD | Four-wheel Drive System, Auxiliary Battery |
| HTR A/C | Climate Control System |
| LOCK | Power Door Lock Relay (Lock Function) |
| HVAC 1 | Inside Rearview Mirror, Climate Control System |
| L DOOR | Driver’s Door Harness Connection |
| CRUISE | CRUISE Control |
| UNLOCK | Power Door Lock Relay (Unlock Function) |
| RR FOG LP | Rear Fog Lamp (Export Only) |
| BRAKE | Anti-Lock Brake System |
| DRIVER UNLOCK | Power Door Lock Relay (Drive’s Door Unlock Function) |
| IGN 0 | PCM, TCM |
| TBC IGN 0 | Truck Body Controller |
| VEH CHMSL | Vehicle and Trailer High Mounted Stoplamp |
| LT TRLR ST/TRN | Left Turn Signal/Stop Trailer |
| LT TRN | Left Turn Signals and Sidemarkers |
| VEH STOP | Vehicle Stoplamps, Brake Module, Electronic Throttle Control Module |
| RT TRLR ST/TRN | Right Turn Signal/Stop Trailer |
| RT TRN | Right Turn Signals and Sidemarkers |
| BODY | Harmess Connector |
| DDM | Driver Door Module |
| AUX PWR 2 | Rear Cargo Area Power Outlet |
| LOCKS | Power Door Lock System |
| TBC 2C | Truck Body Controller |
| FLASH | Flasher Module |
| CB LT DOORS | Left Power Window Circuit Breaker |
| TBC 2B | Truck Body Controller |
| TBC 2A | Truck Body Controller |
Center Instrument Panel Utility Block
The center instrument panel utility block is located underneath the instrument panel, to the left of the steering column.
| Device | Usage |
| SEO | Special Equipment Option |
| TRAILER | Trailer Brake Wiring |
| UPFIT | Upfitter (Not Used) |
| SL RIDE | Ride Control Harness Connection |
| HDLR 2 | Headliner Wiring Connector |
| BODY | Body Wiring Connector |
| HDLNR 1 | Headliner Wiring Connector 1 |
| SPARE RELAY | Not Used |
| CB SEAT | Driver and Passenger Seat Module Circuit Breaker |
| CB RT DOOR | Right Power Window Circuit Breaker |
| SPARE | Not Used |
| INFO | Infotainment Harness Connection |
Underhood Electrical Center
The underhood electrical center is located on the driver’s side of the engine compartment near the battery.
*1 – Gasoline Engine and Fuel Injection Rail #2
*2 – Gasoline Engine and Fuel Injection Rail #1
*3 – Gasoline Engine; Oxygen Sensor
*4 – Gasoline Engine; Oxygen Sensor
*5 – PCM Ignition
| Fuses | Usage |
| GLOW PLUG | Not Used |
| CUST FEED | Gasoline Accessow Power |
| STUD #1 | Auxiliary Power (Single Battery and Diesels Only)/Dual Battery (TP2) Do not install fuse. |
| MBEC | Mid Bussed Electrical Center Power Feed, Front Seats, Right Doors |
| BLOWER | Front Climate Control Fan |
| LBEC | Left Bussed Electrical Center, Door Modules, Door Locks, Auxiliary Power Outlet-Rear Cargo Area and Instrument Panel |
| STUD 2 | Accessory Power/Trailer Wiring Brake Feed |
| ABS | Anti-Lock Brakes |
| VSES/ECAS | Vehicle Stability |
| IGN A | lqnition Power |
| IGN B | lqnition Power |
| LBEC 1 | Left Bussed Electrical Center, Left Door, Truck Body Controller, Flasher Module |
| TRL PARK | Parking Lamps, Trailer Wiring |
| RR PARK | Right Rear Parking and Sidemarker Lamps |
| LR PARK | Left Rear Parking and Sidemarker Lamps |
| PARK LP | Parking Lamps Relay |
| STARTER | Starter Relay |
| INTPARK | Interior Lamps |
| STOP LP | Stoplamps |
| TBC BATT | Truck Body Controller Battery Feed |
| SUNROOF | Sunroof |
| SEO B2 | Off-Road Lamps |
| 4WS | Vent Solenoid Canister/QUADRASTEER Module Power |
| RR HVAC | Rear Climate Control |
| AUX HVAC | Auxiliary Power Outlet – Console |
| IGN 1 | Ignition Relay |
| PCM 1 | Powertrain Control Module |
| ETC/ECM | Electronic Throttle Control, Electronic Brake Controller |
| IGN E | Instrument Panel Cluster, Air Conditioning Relay, Turn Signal/Hazard Switch, Starter Relay |
| RTD | Ride Control |
| TRL B/U | Backup Lamps Trailer Wiring |
| PCM B | Powertrain Control Module, Fuel Pump |
| F/PMP | Fuel Pump (Relay) |
| B/U LP | Back-up Lamps, Automatic Transmission Shift Lock Control System |
| RR DEFOG | Rear Window Defogger |
| HDLP-HI | Headlamp Hiqh Beam Relay |
| PRIME | Not Used |
| SIR | Supplemental Inflatable Restraint System |
| FRT PARK | Front Parking Lamps, Sidemarker Lamps |
| DRL | Daytime Running Lamps (Relay) |
| SEO IGN | Rear Defog Relay |
| TBC IGN1 | Truck Body Controller Ignition |
| HI HDLP-LT | High Beam Headlamp-Left |
| LH HID | Not Used |
| DRL | Daytime Running Lamps |
| IPC/DIC | Instrument Panel CIuster/Driver Information Center |
| HVAC/ECAS | Climate Control Controller |
| CIG LTR | Cigarette Lighter |
| HI HDLP-RT | High Beam Headlamp-Right |
| HDLP-LOW | Headlamp Low Beam Relay |
| A/C COMP | Air conditioning Compressor |
| A/C COMP | Air conditioning Compressor Relay |
| RR WPR | Rear Wiper/Washer |
| RADIO | Audio System |
| SEO B1 | Mid Bussed Electrical Center, HomeLink, Rear Heated Seats |
| LO HDLP-LT | Headlamp Low Beam-Left |
| BTSI | Brake Transmission Shift Interlock System |
| CRANK | Starting System |
| LO HDLP-RT | Headlamp Low Beam-Right |
| FOG LP | Fog lamp Relay |
| FOG LP | Fog Lamp |
| HORN | Horn Fuse |
| HORN | Horn Relay |
| W/S WASH | Windshield and Rear Window Washer Pump Relay |
| W/S WASH | Windshield and Rear Window Washer Pump |
| INFO | OnStar/Rear Seat Entertainment |
| RADIO AMP | Radio Amplifier |
| RH HID | Not Used |
| HORN | Horn |
| EAP | Electric Adjustable Pedals |
| TREC | All-Wheel Drive Module |
| SBA | Supplemental Brake Assist |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
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