Troubleshooting a 2008 Ford F150 Trailer Connector with all Functions not Working

Updated 04/30/2013 | Published 04/26/2013

Question:

I have a 2008 Ford F150 that I am getting no power to the factory plug, both the 4 pin flat and 7 pin connectors. 2 nights ago I had power to the trailer using the 7 pin connector. It was getting dark and rain was in the forecast, so I disconnected the trailer from the truck, and put a bag over the trailer plug and wires to keep them dry. Tonight I hooked the trailer up and I am getting no power to the truck plug. I couldnt find anything in the owners manual about a fuse that would trip everything out on the trailer, is there one? I did check one of the trailer fuses and it was OK.

asked by: Mark

Expert Reply:

You really should not have to put a plastic bag over the trailer connector on your vehicle during rain. It should be protected enough that that would not be necessary. In fact, the plastic bag could actually have collected water and held it to the connector and caused moisture to short out circuits on the connector.

It sounds like a relay or fuse is blown and took out all of the trailer wiring circuits. If you can find the battery junction box you should check the condition of the following fuses

Number 5 trailer brake controller
Number 34 trailer turn signals
Number 42 running lights
Number 44 12 volt accessory line
Number 63 reverse light circuit

I attached an FAQ article on trailer wiring for you to check out also.

expert reply by: Jameson C