Having problems with my 2005 F-350 Super Duty, and the factory trailer brake controls. Last summer, I had very few problems with my controller, and I was pulling a couple different trailers ... a 5th wheel camper, and an 18' enclosed trailer used for my mowing business. Now ... this past few months I have had a TBC fault on my display, even when there is no trailer hooked to it. Everything works fine on my mowing trailer (do not have the camper any longer) EXCEPT no trailer brakes. I've checked the fuse, good there.

Any ideas where to start (except the dealer unless need be). Mowing starts NOW, and the ex makes sure I don't have money for things like this, or food for that matter. Gotta pull my mowing trailer ... gotta have brakes!

 

Recommend testing the trailer's brakes when it is disconnected from your truck. This tells if the problem is in the trailer or not. Hook a 12 volt battery from trailer ground to the brake connection and verify that your brake magnets are energizing (they should buzz). Usually the problem is in the trailer. Corroded wires or poor ground connections are common.

If the trailer is OK, check the brake output signal on the truck's 7-pin connecter. The wiring code is on the cover of the connector. Just read the output voltage from the trailer brake connection to ground when the truck is running and the brakes are applied. You should see something less than 12 volts. If there is no voltage signal then the problem is in truck.

Lou Braun

 

Last time I was hooked to my mowing trailer, I had lights but no brakes. Even in my truck, on the display panel for the brake controller, there are no lights ... and when I go to raise or lower the gain, or apply the brakes manually .. nothing. The screen is blank on the panel on the dash. I get the TBC FAULT on my dashboard. This tends to lead me to believe it is in the truck.

 

Okay ... here's the situation. My controller is bad ... I have found that out. Buying a new one from Ford (through work) is $228.00 (what a joke).

My choices at this point, as I see them, are either to buy a new one ... try and find one at a salvage yard, or put an aftermarket controller on my truck.

Has anyone else faced these choices .. and what did you do?

 

How did you find it was the truck's controller? Did you try the above posters suggestions? These things are pretty bulletproof. Did it throw any codes?

Were you moving at over 10 MPH to test the brakes? The trailer brakes do not operate until the door locks go into autolock. I would test this VERY thoroughly before spending ANY money on a new controller and finding out you have the exact same thing happen.

Does your trailer have an emergency brake cable to hook up to the towing vehicle? If so, put that out and see if the trailer's brakes come on.

Oh yeah...one more thing, the TBC light will come on also when the wiring behind the plug in the back has been exposed to water and has corroded and shorted.

 

I had two different mechanics check it out for me at work. Since there is power TO the controller ... and the brake wire (blue one) from the controller to the 7 pin connector is good .. and seeing how there are NO lights or anything on the controller ... it's pretty much dead.

Yes I was going over 10mph. door auto locked ... etc, etc.

With power TO the connector, and nothing coming from it ... it's the controller. For the difference in price for another one from Ford, and the price of a good aftermarket controller, and a jumper cable ($10) ... that I feel is the way to go.

If I could find one in the junk yard for $100 or less, I would go that way .. but those chances are slim.

Thanks for the suggenstions and trying to help though. I appreciate it.

Dave