Troubleshooting Brakes Locking with a P2 Brake Controller on a 2000 Ford F250

Question:

I have a 2000 f250 4x4 7.3 powerstroke I cannot get brakes to work on trailer I have ran new wiring to brake controller thinking it was the truck I had a 2002 ford f350 before this truck and I wired it and it worked great I used the factory harness on this truck and its either got brakes locked up all time or no brakes at all I have a prodigy controller bout 6 mos old it all worked in other truck but not this one all wiring on trailer has not been tampered wirh

asked by: Donald

Expert Reply:

What does the display read when you are trying to activate the brakes? You said you either get brakes locked up or none at all, is it possible you have the brake light circuit run to the brake output of your 7-way? Or maybe that the circuits could be shorting out to each other.

To test the brake controller I would recommend you cut the blue wire from the controller leaving enough room for you to reattach it and then use a circuit tester to test the wire on the controller side for voltage when you apply the brakes. If voltage is there then you know for a fact that the controller is fine and that the problem lies somewhere else.

Next place to test is the 7-way on your vehicle. Test the brake output circuit for voltage when the brakes are applied. If there is not any voltage there then the problem is most likely on the connector. Look for corrosion or a short and fix as necessary.

If there is voltage there then the problem is on the trailer connector and wiring and should be inspected and repaired as necessary.

I attached an FAQ article on troubleshooting brake controllers that you should find very informative also.

expert reply by: Jameson C