Trailer Brakes Lock Up When In Reverse

[Tomas]

I have a 2003 Ford F150 and the trailer is a dual axle trailer with surge brakes.
I use a 7-pin connector/adapter at the trailer and truck.

I did notice that when I put the truck in reverse gear the reverse lights on the truck are on, but not on the trailer.
So obviously there is a problem but have no clue on how to fix it.

Also, I have a Chevy Tahoe with the same 7-pin connector and it works fine with the trailer.

Any help would be appreciated. This is driving me nuts!!!
Thanks
Tom

[Matt M.]

Had this happen on my 2000 f-150, and my 09. You are missing a fuse, that's all. There is a fuse that will light up the "AUX" (I think) light on the 7 prong. I’m no mechanic, but I know that extra current of electricity unlocks the brakes. It's a constant on, so it won’t matter if you are reverse or not, the current will be running. They may try and tell you that you need all this extra crap, but it's just a couple buck fuse. Guaranteed... Hope this helps man.

[scott39]

had the same problem. Mine was wired to the license plate light. It came loose. repaired it. good to go

[smokenflames]

Get a light tester and check for power at the center post of the plug to the truck. My brother had the same problem and was a fuse. He had it in the dealership and they said nothing wrong. Blown fuse for sure. Or just use the Chevy to tow the boat! Good luck.

[Fred Fullerton]

Yep just trade trucks go to the Chevy and you have no problems. But you need to wire it to back up lights on your ford and that will fix it.

[fharris]

I had the same problem. The fuse they're mentioning is located under the hood on the right side. If you bought your truck new it came with one. If not your ford dealer will have one. Hope this helps.

[Tom Bossard]

Truck should have a separate trailer back up light fuse. You can find it in your owners manual. If it pops again you may have a problem in the trailer wiring.

[mark poulson]

If you're going to fool around with the fuses yourself, take a picture of the fuse box first with your cellphone, so you can be sure you put them back in the right places.
Don't ask me how I figured this one out.

[Chris N]

I had the same problem, 07 Silverado with an 07 Champ, it was a solenoid in the trailer that was bad- very frustrating until my trailer guy replaced the solenoid

[fishndp]

Had a similar problem. Fuse and solenoid both were ok. Turned out to be corrosion on the trailer ground lead.
Cleaned it up and hasn't been a problem since.

[blkdog812]

check to make sure you didnt blow the fuse that is in the fusse box in the engine compartment.