Integrated Trailer Brake Controller on 05' Ford F250....not working right??

[iqraceworks]

I recently picked up a nice used 05’ Ford F250 for pulling our travel trailer. It’s got one of the built in OEM Trailer Brake Controllers (TBC)…..and I can’t seem to get it to work right, I was wondering if any of you guys could point me in the right direction.


When I hook up the 7-way plug for the trailer, the TBC in the truck seems to recognize that there is a trailer hooked up. The display on the TBC turns green, and it allows me to adjust the gain setting on it. But when I have my wife squeeze the manual control on the TBC to send full power to the trailer brakes (gain set on 10), I’m only getting around 1.0v of power out of the pin inside the plug for the brakes…according to my volt meter. I’ve cleaned all the plugs, checked the wiring, everything looks good. The lights all work….just no power to the trailer brakes.



I’m not getting any errors…..it just doesn’t seem to be giving any power to the brakes. Do the integrated brake controllers on those older Ford have some sort of parameters that have to be met before they will apply power to the trailer brakes? Does the truck have to be in (D)rive? Does it have to be moving a certain speed before they start working? I’ve been doing some research online, and it sounds like they are way more complicated than they need to be.



I’m about at the point where I just want to bypass the OEM TBC and install an aftermarket unit.



Any help would be great! Thanks!

[JamieGeek]

You may be measuring it wrong: Is this with the brakes connected or just at the bare plug? (It may need a complete circuit.)

Have you tried using the manual control while driving with the trailer connected? Do the brakes actuate? With our old F-450 and the controller I could completely stop the truck while coasting at idle with the manual control (I usually did that before pulling away to ensure everything was working ok).

I wouldn't put an aftermarket one in, you won't find a better solution than the OEM TBC. Once adjusted properly it puts just about the same "pressure" on the trailer brakes as what the truck is putting on its brakes--its the most seamless braking experience I've had with a trailer.

[16ACE27]

Brake controllers apply voltage to the trailer brakes based on factors other than GAIN. They have to sense the truck is decelerating before they apply any braking so standing still they probably apply very little voltage to the trailer brakes (as you found out).

[iqraceworks]

Thanks for all the info. I did some more searching online, and found out that Ford came out with Technical Service Bulletin for the 05' Trucks with the built in brake controllers. Apparently that year truck, only that year, won't send power to the brakes until you are over 10-15mph....even if you use the manual control on them. All other years will supply power to the brakes while the truck is not moving if you use the manual controls.

So at this point.....I guess I just to just get out and pull the trailer at 20+ mph and manually activate the trailer brakes and see what happens.

Thanks again for all the info!