I have a 2004 f250. Bought used with no owners manual. My trailer brakes quit working. I went to ford dealer and got the fuse diagram. Fuses are good. I switched brake controllers and still no luck. I know the brakes work on my trailer cause my buddy used it with his truck and had no problem. The deal said there is a relay for trailer brakes but could not or would not tell me the location of it. Any ideas????? I'm out of options other then taking it to someone to work on it.

 

Did you test the fuses or look at them?

 

The relay is under the hood. Not sure which one, but if you just switch them around one at a time untill you find the bad or missing one.

 

I moved this to the towing section for some additional help. Check our tech folder as well.

check here for a copy of your owners manual. That should also help to locate which relay is for the towing:

Owner Manuals | fleet.ford.com

 

Check the brake switch located on the brake pedal. We had that problem. It will also affect the cruise control and several other functions of the truck.

 

Fuses or connection between truck and trailer about 99% of the time. Almost never the brake controller.

Steve

 

Agree with RV_Tech. Plus, if you swapped controlelrs and still had the issue, that also points to the controller not being an issue. Start testing the outputs at the rear bumper and go from there.

 

Problem solved..... I bought a new relay and started swapping them out until I found the bad one. Probably not the best way but it worked. Thanks for every ones input.

 

Thanks for reporting back.