Low Trailer Brake Voltage on a 2012 Ford F-350 with Integrated Brake Controller

Updated 07/17/2012 | Published 07/14/2012

Question:

New ford f350. When testing volts at the 7 pin receptacle I receive 13.7 volts on left and right turn terminals while applying brakes but only 6.5 on the electric brake terminal. The trailer brakes do engage when hooked up but I am concerned that I do not get full voltage to them since the reading at the truck is just 6.5. Is this normal.

asked by: David C

Expert Reply:

The out put on the trailer brake pin on the 7-Way is dependent upon how the brake controller is set. The power level of a brake controller can be set aggressively or lower depending on how heavy the load is you are carrying.

The controller in the truck is proportional meaning that if you lightly put pressure on the brakes then it does not send that much voltage back. In a lot of proportional controllers, you actually have to be moving to get the proper voltage sent back when using the brake pedal but the manual override should send the full power (up to what it is set to) back to the trailer connector.

I have also heard that is some cases there is a problem with the pressure transducer; something that the dealership would need to look at.

expert reply by: Michael H