Trailer Running Lights Dont Work
 

Hey guys, my trailer running lights have not been working for a while now on my 2001 F250 Diesel. I looked at the fuses under the hood and none seem to be blown. Any other places I should look? The problem started when the lights would sometimes work, and sometimes not, then one day they didnt work at all anymore. Please help!

There are two fuses for trailer lights. One is called Trailer (I think) and the other is something like Trailer Relay. They're in the owners manual (if you still have it).

That being said, I've had the same problem in the past; blew both fuses, replaced them both... then, with good fuses, still had no running lights on the trailer.
Good Luck man.

Thanks. I looked at the fuses and swapped some relays around to see if that would work, still nothing. I dont have the owners manual but looked online at the fuse diagrams, but didn't help much. What did you end up doing to get them to work?

You didn't mention, so have you checked for power at the trailer plug? If the lights were working periodically, it sounds like a connector problem. Maybe corrosion or a broken wire?

yeah, def check for power at the connector.

Me, I just trailered during the day. I also think my issue may have been specific to the trailer... (I hope)

Typically trailer light problems can be traced to a ground issue. You didn't mention if it was a 4-wire or 6 setup, but regardless there is a ground wire on both sides (vehicle and trailer). I'd start by checking the ground wire where it terminates on the trailer and make sure it isn't broken or corroded.
You can also try running a separate wire from a good trailer grounding point (no paint or corrosion - metal only) to a like point on the tow vehicle and see if that doesn't lighten things up :-X05

EDIT: Here's a good site that might help you out:
etrailer.com | Trailer Wiring Diagrams

The usual culprit is the ground connection at the trailer frame.

Thanks for the advice guys. I havent had a chance to dig any more yet, but I do know its not the trailer because I hooked it up to my friends truck and everything work.. so its something on my end, unfortunately. And yes, its a 6 way plug.

2 years ago I had a similar problem with my 2000 F250. Finally traced the problem to a corroded connector about 18 inches back from the trailer plug (up near the spare tire). Cleaned it and all worked OK. As a suggestion, check that out first... I spent a bit of time tracing power from the front of the truck - my running light relay is almost beyond reach behind and below the radio. Not easy to get to.

Well.... you're half-way done then! Keep us posted. :-X22

I put new wires and plug on my trailer. but in my truck plug I'm not getting 12 volts on my running lights now my break, single and fasher I get 12 on my right and left.