Trailer Running Lights Out

[rescuebill]

My 05 F-350 6.0 4x4 trailer running light circuit is dead. No trailer running lights. Truck running lights work fine. No power to the back the inner trailer plug connector. No blown fuses under dash or fuse block under hood. I jumped power to brown/white trailer running light wire under the under hood fuse block, trailer running lights come on. Problem is somewhere upstream of there.

Last time I towed, no problems. This time, no trailer running lights. No problems with trailer, or any other electrical issues.

I hate to chop the harness and put in a relay with new power feed, but don't seem to have any options. My Power Stroke mechanic buddy said he has had the main fuse block not send power to the trailer fuse block, suggested replacing the main fuse block.

Anyone have a similare problem?

[mike 6.0]

did you check 4 way and 5 way for power? You could run a wire from your tail light till you find the wire break. How did the fuse look under hood when you pulled it?

[rescuebill]

There is no power to the plugs under the bumper, either the inner or the outer plugs. I can splice it, I would just rather find the problem and fix it.

The fuses are not popped or burned. No signs of distress.

[brinker]

So there is no power to the fuses?

[06BigRedPowerstroke]

I had this problem with brake lights. I cant really remember what fuse i replaced kinda thinking it was under the hood. I know there is a fuse panel behind the glove box check that out.

[SuperCrutyPS]

Just asking because I don't know, but is there a relay on that circuit? If so, could the relay have gone bad? Just throwing it out as something else to check.

[melmount]

should be fuse 4 under the hood. IS there power going that far?

[knostroke]

maybe just need a new plug

[killacal]

Did you ever get a solution to this problem? I'm having the same exact issue right now.

[dazdillenger]

I just went through the same thing. If the fuse is good, you will likely need to replace the entire fuse box. I spent hours searching for a relay, only to find that the trailer running lights use a relay that is soldered into the fuse block, and not user servicable. I replaced my fuse block, good as new.