What Could Cause 12V Trailer Power Pin to Go Out on 2008 GMC Sierra 7-Way Socket
Updated 07/03/2024 | Published 06/24/2024 >
Products Featured in This Question
Question:
On my 2008 gmc sierra trailer plug everything works except for the 12v pin. Where would the fuse be for this? What else could be the cause?
asked by: Jim
Expert Reply:
Hey Jim, thanks for reaching out!
I took a look in the online owner's manual for your 2008 GMC Sierra and it looks like in the J-Case there's a fuse number 68 that has something to do with the 12V trailer power, but the manual made it sound like you might need to connect a stud or something like that to get it up and running.
If the fuse looks good then the next thing to look at is the OEM wiring itself. This can be a bit difficult to follow sometimes and so you may end up just running your own 10 Gauge Wire # 10-1-1 and routing that through a 40A Circuit Breaker # PK54540 to bypass the OEM wiring.

Jim
7/3/2024
The 40 amp fuse was missing. It was one of the square ones. Replaced it and I have power. Thanks again. Jim

Product Page this Question was Asked From
Continue Researching
- Article: Parts Needed to Add Electric Drum Brakes to a Trailer
- Q&A: What Gauge Wire Should be Used to Wire Trailer Brakes
- Article: Trailer Wiring Diagrams
- Q&A: What Size Wire And Circuit Breaker Should Be Used For The 12v Circuit On A 7-Way?
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Parts Needed to Add Brakes to Ranger Boat Trailer
- Q&A: Recommended Front Hitch and TorkLift Tie Downs for a 2026 Ram 2500 Diesel w/a Factory Hitch
- Q&A: Recommended Built-In Convection Microwave to Replace a 0.9 Cu Ft Furrion Microwave Model FMSN09BL
- Q&A: Instructions to Wire a Trailer for Electric Brakes
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Q&A: Parts Needed to Add Brakes to 3,500 lb Trailer Axle
- Article: Breakaway Kit Installation for Single and Dual Brake Axle Trailers
- Article: How to Measure Your Trailer Wheel Bolt Pattern


Jim
7/3/2024
Thank you so much for this information. It has given me a place to start and possible corrections for my problem. Jim