Low Brake Output Voltage With Factory Brake Controller On a 2009 Ford F-350

Question:

Hi I followed all your comments on how much voltage should be coming out of the controller. I placed a volt meter and when I activate the controller manually, I get from 8 to 12 volts but when I press the brake pedal all I get is 1 volt. When driving if I actuate the brakes manually, the trailer feels as if I had the gain at at low setting but is it at full setting. I replaced all four brakes with new kit that came together with pads and new magnets. I’m still having the same problem. Trailer ground is good and magnets are good as well. Thank you for your help.

asked by: Lorenzo

Expert Reply:

For starters, the oem brake controller on your 2009 Ford F-350 has a proportional design which means it would not put out 12 volts or anywhere close while using the brake pedal at a stop. That said, if you are having issues with weak brakes while in motion then there could be a few other issues. The first thing I recommend you do is make sure the brake controller is turned all the way up and then start testing the wire from the vehicle connector all the way back to the magnets with the override applied.

If you drop below say 11 volts or so before you get to the magnets then most likely you have a short in the wire somewhere. If you are say over 11 volts before the magnets then the braking assemblies most likely just need to be adjusted. I am not sure where you were testing for voltage so some of this you may have already been done but I also recommend you check the output wire directly behind the controller to make sure you are getting a full 12 volts because if not the oem brake controller is bad and will need to be replaced for which I recommend the Tekonsha Prodigy P2 part # 90885 with the Tekonsha Plug-In Wiring Adapter part # 3034-P.

expert reply by: Conner L