Troubleshooting Fuses and Relays for 12V Power on 7-Way Trailer Connector of 2008 Ford F-450

Question:

I have a 2008 Ford F4 50 I have no power to the 12 V wire on my plug in the rear of the truck I do not have the owners manual I don’t know where the fuse is for that I appreciate any help you can give me thank you

asked by: Loren J

Helpful Expert Reply:

I looked up your owners manual in a web search and was able to find that fuse 33 in the fuse box in the passenger side of your cab is one place to check. Relay 44 and relay 56 in the engine bay power distribution box also impact that 12v Power at your trailer connector.

With relays testing isn't easy so simply replacing them with one you know works is the best option. Then you can use a circuit tester like # PTW2993 to test your 7-way at the 1 o'clock position for power.

expert reply by: Jason S