What Could Cause Fuse on Truck to Blow When Trailer Wiring is Connected

Question:

Our 2012 Ford F250 diesel truck keeps blowing a 25 amp fuse every time I tow any kind of trailer. When the fuse blows, I no longer have brake lights on the trailer. I have towed several different trailers, so I know it is not the trailers, it has got to be something with the F250. Any suggestions?

asked by: Sharon F

Expert Reply:

Wiring shorts are typically what cause fuses to blow when trailer wiring is connected. Most likely there's a short on the trailer connector wiring which is causing the issue you are having. This is typically caused by exposed wire behind the trailer wiring connector. That said since you didn't mention the exact fuse that is blowing it's harder to say for sure since that is a big clue on where the short might be.

Another easy thing to check is the pins of the connector for corrosion. Cleaning that off with sandpaper normally takes care of most trailer wiring issues.

I attached a help article on troubleshooting trailer wiring shorts for you to check out as well.

expert reply by: Jameson C