12 Volt Power At Trailer Connector Not Functioning on 2011 Ford F250

Question:

Hi i have a 2011 FORD F250 Diesel truck everything works on the 7way plug on truck but I don’t have 12volt terminal hot

asked by: John

Expert Reply:

You likely have a bad or missing fuse or relay in the power distribution box under the hood. Look for a 25A fuse in position 90 and a relay in position # 102. Examine the fuse and replace if necessary. It's not typically possible to look at a relay and be able to determine if it's bad, but you can replace it with an adjacent relay to see if that activates the circuit.

If that doesn't fix the problem, given the fact that the vehicle is 8 years old, before taking it to the dealer, I'd just abandon the OEM power feed from the battery to the trailer connector and install my own. You'll need a length of 10 gauge wire, part # 10-1-1 long enough to extend from the positive battery terminal to the trailer connector, a 40 amp breaker # 9510, two # 44-5310A ring terminals, a # DW05705-1 ring terminal and # DW05745-5 heat shrink butt connectors.

Locate the wire feeding the pin in the 1:00 position on the trailer connector as shown in the photo. Several inches behind the trailer connector, cut the wire. Use the butt connector to attach the length of 10 ga wire, and route it up to the battery. Avoid anything hot or moving like exhaust, drivetrain or suspension components. Near the battery, possibly on the inner fender mount the breaker. Attach the wire to the silver terminal using the ring terminal. Using a short length of the wire, make a jumper to go from the copper terminal to the positive battery terminal. This will provide a circuit protected 12-v accessory circuit.