The Chevrolet Avalanche (2001-2006) on the GMT800 platform combines the utility of a pickup truck with the comfort of an SUV. Key features include its versatile midgate, allowing the cargo area to expand into the passenger cabin, along with powerful V8 engine options and a smooth, stable ride. The Avalanche also offers advanced features like automatic climate control, power windows, and premium audio systems, all reliant on its electrical system.
The fuse box, located under the hood and inside the cabin, safeguards crucial systems like the headlights, power seats, and air conditioning by cutting off power if an electrical surge occurs. If a fuse blows, replacing it restores functionality to the affected system.
The relays manage high-current operations such as the fuel pump, cooling fan, and starter motor. These relays act like switches to ensure that the truck’s major electrical components work efficiently. A malfunctioning relay can cause issues like starting problems or a non-operational cooling system.
Maintaining the fuse box and relays is essential to ensuring the Avalanche’s electrical systems run smoothly, keeping its many features functioning properly for both utility and comfort.
MUST READ: DYI – How to Check Car Fuses?
(2001-2006) Chevrolet Avalanche (GMT800) fuse box and relay with Diagram
WARNING
- Never replace a fuse with one that has a higher amperage rating.
- A fuse with a too-high amperage could damage the electrical part and cause a fire.
- On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
- If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
- Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Chevrolet Avalanche (GMT800) 2001-2006 fuse assignment
- Cigar lighter / power outlet fuses in the Chevrolet Avalanche are located in the Engine Compartment fuse box. 2001-2002 – see fuses “AUX PWR” and “CIGAR”. 2003-2006 – see fuses “AUX PWR” (Auxiliary Power Outlet – Console), “CIG LTR” (Cigarette Lighter) in the Engine Compartment fuse box and fuse “AUX PWR 2, M/GATE” (Rear Cargo Area Power Outlets, Midgate) in the Instrument Panel Fuse Box.
Year of production: from 2001, 2002, 2003, 2004, 2005, 2006
Fuse Box Location
Instrument Panel
The fuse box is located on the side of the instrument panel, on the driver’s side, behind the cover.
Center instrument panel relay box
The center instrument panel utility block is located underneath the instrument panel, to the left of the steering column.
Engine Compartment
Engine Compartment Additional Fuse Block (if equipped)
The auxiliary electric cooling fan fuse block is located in the engine compartment on the driver’s side of the vehicle next to the underhood fusebox.
Fuse box diagrams
2001, 2002
Instrument Panel
Assignment of the fuses in the instrument panel (2001-2002)
| Name | Usage |
|---|---|
| L BODY | Retained Accessory Power Relay |
| LOCK | Power Door Locks |
| DRV UNLOCK | Power Door Lock Relay |
| LOCK | Power Door Lock Relay |
| HVAC 1 | Climate Control System |
| CRUISE | Cruise Control, Instrument Cluster |
| IGN 3 | Ignition, Power Seats |
| 4WD | Four-Wheel Drive System, Auxiliary Battery |
| CRANK | Starting System |
| INT PRK | Interior Lamps |
| L DOOR | Power Door Lock Relay |
| BRAKE | Anti-Lock Brake System |
| RR WIPER | Not Used |
| ILLUM | Interior Lamps, Cargo Lamps |
| SEAT | Power Seat Circuit Breaker |
| TURN | Exterior Lamps, Turn Signals, Hazard Lamps |
| UNLOCK | Power Door Locks |
| HTR A/C | Climate Control System |
| WS WPR | Windshield Wipers |
| IGN 1 | Ignition, Instrument Panel |
| AIR BAG | Air Bag |
| MIR/LOCK | Power Mirrors, Power Door Locks |
| DR LOCK | Power Door Locks |
| PWR WDO | Power Window Circuit Breaker |
| UNLOCK | Power Door Lock Relay |
| IGN 0 | PRND321 Display, Odometer, VCM/PCM |
| SEO IGN | Special Equipment Option, Ignition |
| SEO ACCY | Special Equipment Option Accessory |
| RAP #1 | Retained Accessory Power Relay |
| RDO 1 | Audio System |
| RAP #2 | Rear Power Windows, Sunroof, Radio |
Center instrument panel relay box
Center instrument panel relay box (2001-2002)
| Relay | Usage |
|---|---|
| SEO | Special Equipment Option |
| HTD ST | Heated Seats |
| SPARE | Not Used |
| VANITY | Headliner Wiring |
| TRAILER | Trailer Brake Wiring |
| PWR ST | Power Seats |
| SPARE | Not used |
| UPF | Upfitter |
| PARK LAMP | Parking Lamps |
| FRT PRK EXPT | Not Used |
| SPARE 2 | Not Used |
| PUDDLE LP | Puddle Lamps |
| SL RIDE | Not Used |
| SPARE 3 | Not Used |
| INADV PWR | Interior Lamps Feed |
| CTSY LP | Courtesy Lamps |
| CEL PHONE | Cellular Telephone Wiring |
Engine Compartment
Assignment of the fuses and relay in the engine compartment (2001-2002)
| Name | Usage |
|---|---|
| STUD #1 | Accessory Power/Trailer Wiring Feed/Load Leveling |
| ABS | Anti-Lock Brakes |
| IGN A | Ignition Switch |
| AIR | A.I.R. System |
| RAP #1 | Retained Accessory Power, Power Mirrors, Power Door Locks, Power Seat(s) |
| IGN B | Ignition Switch |
| RAP #2 | Retained Accessory Power/Rear Power Windows, Sunroof, Radio |
| STUD #2 | Accessory Power/Trailer Wiring Brake Feed |
| TRL R TRN | Right Turn Signal Trailer Wiring |
| TRL L TRN | Left Turn Signal Trailer Wiring |
| IGN 1 | Ignition, Fuel Controls |
| INJ-B | Ignition, Fuel Controls (Relay) |
| STARTER | Starter (Relay) |
| PARK LP | Parking Lamps |
| FRT HVAC | Climate Control System |
| STOP LP | Exterior Lamps, Stoplamps |
| ECM 1 | VCM/PCM |
| CHMSL | Center High Mounted Stoplamp |
| VEH STOP | Stoplamps, Cruise Control |
| TRL B/U | Backup Lamps Trailer Wiring |
| INJ-A | Fuel Controls, Ignition |
| RR HVAC | Not Used |
| VEH B/U | Vehicle Backup Lamps |
| ENG 1 | Engine Controls, Canister Purge, Fuel System |
| ETC | Electronic Throttle Control |
| IGN E | A/C Compressor Relay, Rear Window Defogger, Daytime Running Lamps, A.I.R. System |
| B/U LP | Backup Lamps, Automatic Transmission Shift Lock Control System |
| ATC | Automatic Transfer Case |
| RR DEFOG | Rear Window Defogger, Heated Mirrors (Relay) |
| RTD | Not Used |
| RR PRK | Right Rear Parking Lamps |
| ECM B | VCM/PCM |
| F/PMP | Fuel Pump (Relay) |
| O2 A | Oxygen Sensors |
| O2 B | Oxygen Sensors |
| LR PRK | Left Rear Parking Lamps |
| RR DEFOG | Rear Window Defogger, Heated Mirrors |
| HDLP | Headlamps (Relay) |
| TRL PRK | Parking Lamps Trailer Wiring |
| PRIME | Not Used |
| RT HDLP | Right Headlamps |
| DRL | Daytime Running Lamps (Relay) |
| HTD MIR | Heated Mirrors |
| LT HDLP | Left Headlamps |
| A/C | Air Conditioning |
| AUX PWR | Cigarette Lighter, Auxiliary Power Outlets |
| SEO 2 | Special Equipment Option Power, Power Seats, Aux Roof Mnt Lamp |
| SEO 1 | Special Equipment Option Power, Aux Roof Mnt Lamp |
| DRL | Daytime Running Lamps |
| A/C | A/C (Relay) |
| FOG LP | Fog Lamps |
| FOG LP | Fog Lamps (Relay) |
| RADIO | Audio System, Instrument Cluster, Climate Control System |
| CIGAR | Cigarette Lighter, Auxiliary Power Outlets |
| RT TURN | Right Turn Signals |
| BTSI | Automatic Transmission Shift Lock Control System |
| LT TURN | Left Turn Signals |
| FR PRK | Front Parking Lamps, Sidemarker Lamps |
| W/W PMP | Windshield Washer Pump |
| HORN | Horn (Relay) |
| IGN C | Ignition Switch, Fuel Pump, PRND321 Display, Crank |
| RDO AMP | Radio Amplifier |
| HAZ LP | Exterior Lamps, Hazard Lamps |
| EXP LPS | Not Used |
| HORN | Horn |
| CTSY LP | Interior Lamps |
| RR WPR | Not Used |
| TBC | Body Control Module, Remote Keyless Entry, Headlamps |
2003, 2004, 2005, 2006
Instrument Panel
Assignment of the fuses in the instrument panel (2003-2006)
| Name | Usage |
|---|---|
| RR Wiper | 2003-2005:Rear Window Wiper Switch 2006: Not Used |
| 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 |
| HTR A/C | Climate Control System |
| LCK | Power Door Lock Relay (Lock Function) |
| HVAC 1 | Inside Rearview Mirror, Climate Control System |
| LT DR | 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 (Driver’s Door Unlock Function) |
| IGN 0 | Powertrain Control Module, Transmission Control Module |
| 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 |
| BODY | Harness Connector |
| RT TRLR ST/TRN | Right Turn Signal/Stop Trailer |
| RT TRN | Right Turn Signals and Sidemarkers |
| DDM | Driver Door Module |
| AUX PWR 2, M/GATE | Rear Cargo Area Power Outlets, Midgate |
| LCKS | Power Door Lock System |
| ECC, TPM | Rear Electronic Climate Control, Tire Pressure Monitoring System (If Equipped) |
| TBC 2C | Truck Body Controller |
| FLASH (2003-2005) HAZRD (2006) | Flasher Module |
| CB LT DRS | Left Power Window Circuit Breaker |
| TBC 2B | Truck Body Controller |
| TBC 2A | Truck Body Controller |
Center instrument panel relay box
Center instrument panel relay box (2003-2006)
| Relay name | Usage |
|---|---|
| SEO | 2003-2005: Special Equipment Option 2006: Special Equipment Option/Off-road Lamps Harness Connector |
| TRAILER | Trailer Brake Wiring |
| UPFIT | Upfitter (Not Used) |
| SL RIDE | 2003-2005: Ride Control Harness Connection 2006: Ride Control (Not Used) |
| HDLR 2 | Headliner Wiring Connector |
| BODY | Body Wiring Connector |
| DEFOG | Rear Defogger Relay |
| HDLNR 1 | Headliner Wiring Connector 1 |
| SPARE RELAY | Not Used |
| CB SEAT | Driver and Passenger Seat Module Circuit Breaker |
| CB RT DOOR | 2003-2005: Right Power Window Circuit Breaker 2006: Rear Right Power Window, Passenger Door Module |
| SPARE | Not Used |
| INFO | 2003-2004: Infotainment Harness Connection 2005-2006: Not Used |
Engine Compartment Fuse Box (2003-2005)
*1 — Gasoline Engine and Fuel Injection Rail #2;
*2 — Gasoline Engine and Fuel Injection Rail #1;
*3 — Gasoline Engine; Oxygen Sensors;
*4 — Gasoline Engine; Oxygen Sensors;
*5 — PCM Ignition.
Assignment of the fuses and relay in the engine compartment (2003-2005)
| Name | Usage |
|---|---|
| GLOW PLUG | Not Used |
| CUST FEED | Accessory Power |
| HYBRID | Hybrid |
| STUD #1 | Auxiliary Power |
| 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 | Ignition Power |
| IGN B | Ignition Power |
| LBEC 1 | Left Bussed Electrical Center, Left Doors, 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 PWR | Auxiliary Power Outlet — Console |
| IGN 1 | Ignition Relay |
| PCM 1 | Powertrain Control Module |
| ETC/ECM | Electronic Throttle Control, Electronic Brake Controlle |
| INJ 1 | Ignition Coil, Fuel Injectors–Bank 1 |
| INJ 2 | Ignition Coil, Fuel Injectors–Bank 2 |
| IGN E | 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) |
| O2A | Oxygen Sensors |
| B/U LP | Back-up Lamps, Automatic Transmission Shift Lock Control System |
| RR DEFOG | Rear Window Defogger |
| HDLP-HI | Headlamp High Beam Relay |
| PRIME | Not Used |
| O2B | Oxygen Sensors |
| 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 | Left Hand High Intensity Discharge Lamps |
| DRL | Daytime Running Lamps |
| IPC/DIC | Instrument Panel Cluster/Driver Information Center |
| HVAC/ECAS | Climate Control Controlle |
| CIG LTR | Cigarette Lighter |
| HI HDLP-RT | High Beam Headlamp-Right |
| HDLP-LOW | Headlamp Low Beam Relay |
| A/C COMP | Air Conditioning Compressor Relay |
| A/C COMP | Air Conditioning Compressor |
| RR WPR | Rear Wiper/Washe |
| 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 Lamps |
| 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 | Right Hand High Intensity Discharge Lamp |
| HORN | Horn Fuse |
| EAP | Electric Adjustable Pedals |
| TREC | All-Wheel Drive Module |
| SBA | Supplemental Brake Assist |
Engine Compartment Fuse Box (2006)
*1 — Gasoline Engine and Fuel Injection Rail #2;
*2 — Gasoline Engine and Fuel Injection Rail #1;
*3 — Gasoline Engine; Oxygen Sensors;
*4 — Gasoline Engine; Oxygen Sensors;
*5 — Ignition 1;
*6 — Powertrain Control Module, Fuel Pump;
*7 — Rear Climate Control;
*8 — Sunroof.
Assignment of the fuses and relay in the engine compartment (2006)
| Name | Usage |
|---|---|
| GLOW PLUG | Not Used |
| CUST FEED | Accessory Power |
| HYBRID | Not Used |
| STUD #1 | Auxiliary Power |
| 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 | Automatic Level Control (ALC) Compressor |
| IGN A | Ignition Power |
| IGN B | Ignition Power |
| LBEC 1 | Left Bussed Electrical Center, Left Doors, 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 |
| STRTR | Starter Relay |
| INTPARK | Interior Lamps |
| STOP LP | Stoplamps |
| TBC BATT | Truck Body Controller Battery Feed |
| SEO B2 | Off-Road Lamps |
| 4WS | Vent Solenoid Canister/Quadrasteer Module Power |
| AUX PWR | Accessory Power Outlet — Console |
| 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 | Electronic Suspension Control, Automatic Level Control (ALC) Exhaust |
| TRL B/U | Backup Lamps Trailer Wiring |
| 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 High Beam Relay |
| PRIME | Not Used |
| AIRBAG | 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 | Driver’s Side High Beam Headlamp |
| LH HID | Left Hand High Intensity Discharge Lamps |
| DRL | Daytime Running Lamps |
| RVC | Regulated Voltage Control |
| IPC/DIC | Instrument Panel Cluster/Driver Information Center |
| HVAC/ECAS | Climate Control Controller |
| CIG LTR | Cigarette Lighter |
| HI HDLP-RT | Passenger’s Side High Beam Headlamp |
| HDLP-LOW | Headlamp Low Beam Relay |
| A/C COMP | Air Conditioning Compressor Relay |
| A/C COMP | Air Conditioning Compressor |
| TCMB | Transmission Control Module |
| RR WPR | Not Used |
| RADIO | Audio System |
| SEO B1 | Mid Bussed Electrical Center, Universal Home Remote System, Rear Heated Seat |
| LO HDLP-LT | Driver’s Side Headlamp Low Beam |
| BTSI | Brake Transmission Shift Interlock System |
| CRANK | Starting System |
| LO HDLP-RT | Passenger’s Side Headlamp Low Beam |
| FOG LP | Fog Lamp Relay |
| FOG LP | Fog Lamps |
| HORN | Horn Relay |
| W/S WASH | Not Used |
| W/S WASH | Not Used |
| INFO | OnStar/Rear Seat Entertainment |
| RADIO AMP | Radio Amplifier |
| RH HID | Right Hand High Intensity Discharge Lamp |
| HORN | Horn Fuse |
| EAP | Electric Adjustable Pedals |
| TREC | All-Wheel Drive Module (If Equipped) |
| SBA | Supplemental Brake Assist |
Engine Compartment Additional Fuse Block
Engine Compartment Additional Block (2005-2006)
| Fuses | Usage |
|---|---|
| COOL/FAN | Cooling Fan |
| COOL/FAN | Cooling Fan Relay Fuse |
| COOL/FAN | Cooling Fan Fuse |
| Relays | |
| COOL/FAN 1 | Cooling Fan Relay 1 |
| COOL/FAN 3 | Cooling Fan Relay 3 |
| COOL/FAN 2 | Cooling Fan Relay 2 |
Conclusion
For owners and enthusiasts of classic Chevrolet Avalanche (GMT800) 2001-2006, understanding the fuse box and relay systems is essential for vehicle maintenance. Regular inspection and maintenance of these components helped ensure the vehicle’s longevity and reliability, preserving its status as a symbol of Chevrolet’s craftsmanship and innovation in the automotive industry during that era.
