Forum Discussion

imq707s's avatar
imq707s
Explorer
Mar 22, 2018

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

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?

Any help would be great! Thanks!
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  • TakingThe5th's avatar
    TakingThe5th
    Explorer
    Mar 22, 2018
    rctaw wrote:
    It seems that I remember the early F250/350 controllers would not activate the brakes if you were stopped or if you were traveling under 10 or 15 mph. Sorry I can't remember the year models though. It should be easy to check by visiting the the ford truck forums and doing a search. I am sure someone here will chime in soon enough with the facts as well.

    X2. That's exactly how my 2005 F350 works.
  • imq707s's avatar
    imq707s
    Explorer
    Mar 22, 2018
    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!
  • rctaw's avatar
    rctaw
    Explorer
    Mar 22, 2018
    It seems that I remember the early F250/350 controllers would not activate the brakes if you were stopped or if you were traveling under 10 or 15 mph. Sorry I can't remember the year models though. It should be easy to check by visiting the the ford truck forums and doing a search. I am sure someone here will chime in soon enough with the facts as well.
  • Super_Dave's avatar
    Super_Dave
    Explorer
    Mar 22, 2018
    When you push on the brake pedal are you getting increasing brake pressure readings on the controller?

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