No 12V Power Or Trailer Brake Power To 7 Way Plug on 2007 GMC 2500HD

Question:

I Have A 2007 GMC 2500HD My 7 Way Plug Has No Power To Red 12V Wire And No Power To Blue Trailer Brake Wire.

asked by: Alan L

Expert Reply:

If both the 12V and trailer brake circuits on your 7-way have failed at or about the same time the most likely culprit is a corroded or damaged 7-way socket. You can inspect it for any signs of even very slight greenish or whitish discoloration on the contact surfaces. Check both sides of the 7-way. Sometimes if corrosion builds up it can actually bridge two circuits together, causing a short and malfunction of the affected circuits.

If you find any evident corrosion clean or replace the socket as needed. You can also check your power distribution box for any blown fuses.

With a circuit tester like # PTW2993 you can also test the blue wire at your brake controller; this is the output circuit wire that feeds the 7-way. If you have signal on the blue wire when you step on the brake or press the manual override, then you know the controller is working and that the problem is downstream in the wiring or connector.

You can also test the wires going into the 7-way to see if the signals are present on this wiring. If the signals appear on the wires but not at the 7-way pins, then you know the connector is bad and needs to be replaced. The linked article will give you additional troubleshooting tips.

expert reply by: Adam R