In this article you will find a description of fuses and relays HUMMER,
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.
Instrument Panel Fuse Block
The fuse block access door is located 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 | Rear Heated Seats Module |
4WD | Four-Wheel Drive Switch, Air Suspension Switch/Module |
HTR A/C | Not Used |
LOCK | Power Door Lock Relay |
HVAC 1 | Inside Rearview Mirror, Climate Control System |
L DOOR | Harness Connection |
CRUISE | Cruise Control |
UNLOCK | Power Door Lock Relay |
RR FOG LP | Not Used |
BRAKE | Brake Switch |
IGN 0 | Brake Transmission Shift Interlock, Powertrain Control Module, Transmission |
TBC IGN 0 | Truck Body Controller |
VEH CHMSL | Vehicle and Trailer Center High Mounted Stop Lamp |
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 | Instrument Panel and Rear Cargo Area Power Outlets |
LOCKS | Rear Doors and Liftgate Power Lock Relay Feed |
ECC | Not used |
TBC 2C | Truck Body Controller |
FLASH | Flasher Module |
CB LT DOORS | Left Rear Power Window Circuit Breaker and Driver Door Module |
TBC 2B | Truck Body Controller |
TBC 2A | Truck Body Controller |
Center Instrument Panel Fuse 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/Off-Road Lamps Harness Connector |
TRAILER | Trailer Brake Wiring |
UPFIT | Upfitter (Not Used) |
SL RIDE | Ride Control (Not Used) |
HDLR 2 | Headliner Wiring Connector 2 |
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 | Rear Right Power Window, Passenger Door Module |
SPARE | Not Used |
INFO | Infotainment Unit (Not Used) |
Underhood Fuse Block
The underhood fuse block in the engine compartment is located on the driver’s side of the vehicle near the battery.
Fuses | Usage |
STUD #1 | Accessory Power/Trailer Wiring |
MBEC 1 | Mid Bussed Electrical Center Power Feed, Front Seats, Right Doors |
BLOWER | Front Climate Control Fan |
LBEC 2 | 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 | (ECAS) Electronically Controlled Air Suspension |
IGN A | Ignition Switch |
IGN B | Ignition Switch |
LBEC 1 | Left Bussed Electrical Center, Left Doors, Truck Body Controller, Flasher Module |
TRL PARK | Parking Lamps Trailer Wiring |
RR PARK | Passenger’s Side Rear Parking and Sidemarker Lamps |
LR PARK | Driver’s Side Rear Parking and Sidemarker Lamps |
PARK LP | Parking Lamps Relay |
STRTRER | Starter Relay |
INTPARK | Roof Marker Lamps |
STOP LP | Stoplamps |
TBC BATT | Truck Body Controller Battery Feed |
SEO B2 | Off-Road Lamps |
4WS | Vent Solenoid Canister |
RR HVAC | Not Used |
AUX PWR | Auxiliary Power Outlet — Console |
IGN 1 | Ignition Relay |
PCM 1 | Powertrain Control Module |
ETC/ECM | Electronic Throttle Control, Electronic Brake Controller |
INJ 1 | Ignition Coil, Fuel Injectors-Bank 1 |
INJ 2 | Ignition Coil, Fuel Injectors-Bank 2 |
IGN E | Instrument Panel Cluster, Air Conditioning Relay, Turn Signal/Hazard Switch, Starter Relay, Electronic Brake Controller TC2 Mode Switch |
RTD | Electronic Brake Controller Battery Feed |
TRL B/U | Backup Lamps Trailer Wiring |
PCM B | Powertrain Control Module, Fuel Pump |
F/PMP | Fuel Pump Relay |
02A | 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 | Not Used |
DRL | Daytime Running Lamps |
IPC/DIC | Instrument Panel Cluster/ Driver Information Center |
HVAC/ECAS | Climate Control Controller/Electronically Controlled Air Suspension |
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, Rear Heated Seats, HomeLink |
LO HDLP-LT | Headlamp Low Beam-Left |
BTSI | Brake Transmission Shift Interlock System |
CRNK | Starting System |
LO HDLP-RT | Headlamp Low Beam-Right |
FOG LP | Not Used (Relay) |
FOG LP | Not Used |
HORN | Horn Relay |
W/S WASH | Windshield and Rear Window Washer Pump Relay |
W/S WASH | Windshield and Rear Window Washer Pump |
INFO | OnStar |
RADIO AMP | Radio Amplifier |
RH HID | Not Used |
HORN | Horn |
EAP | Not Used |
TREC | All-Wheel Drive Module |
SBA | Not Used |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Still have questions or want to supplement the article? Discuss On Telegram