Troubleshooting Brake Controller Not Sending Power Back from Ford F-150 to Trailer

Question:

Hello, Im working on trailer brake on a bran new trailer and a bran new control box in truck of older f150, been having problems for a while, Ive used factory harness and Ive ran my ove new wires back to plug and still no cigar, I guess one thing that comes to mind is I know there is suposto be a positive wire in the plug for charging and I dont believe that is live , would that make a difference

asked by: Tedd B

Expert Reply:

First thing I'd do is test the plug on your F-150 for function. Use a circuit tester like part # PTW2979 and check the pin in the 5 o'clock position while you're sending power back to the 7-Way with your manual override. If you get power then the problem is on your trailer. If you don't get power then the issue is on your truck.

What is probably happening is you have a proportional controller that has a sensor and only sends power back to the 7-Way when you use the manual override and/or when you're in motion.

If that isn't the case then the issue is with the wiring on your truck or trailer. Typically it's going to be a bad ground that needs to be reconnected to a clean, bare-metal surface.

If you are still having issues after this let me know and I can help you troubleshoot further.

expert reply by: Jon G