Hey there, folks! I checked around on the forum, but I wasn't able to find an answer for my 2006 F-250 6.0L Lariat.

My boyfriend had accidentally plugged the trailer lights in upside-down. Since then, I haven't gotten any running (accessory) lights to work, no matter what I've hooked up to. For the most part, I still have brake/turn signals so I've been able to get by. When I hooked up to our gooseneck, I had no lights at all (although I don't have 100% faith in those lights to begin with). My dad originally blamed the ground in the truck, but recalling the oopsie by my other half I'm starting to ponder. We were able to borrow another trailer and use the hookup for the bumper in the bed by disconnecting it and fishing it under the tailgate. At that point I had brake/turn signals, but still no running lights.

I checked the 30 AMP fuses (under the hood) as well as the 10 AMP fuse under the dash and they all appear fine? I questioned the 10 with the connectors looking the way they do. But again, ¯\_(ツ)_/¯
I'm not sure what I should be looking for next or if it's simply the 10a fuse after all?

All the gratitude!

 

Well, first easy trouble shooting step would be to replace fuses. They are cheap and easy to swap, so it's probably worth doing just to be safe. I have had ones that looked ok, but were still bad in the past.

The second trailer having the same problem points to some issue with your tow rig. I'd say start by replacing fuses, then test the individual circuits on your truck plug with a multi-meter or test light. If one doesn't work, start working along the wiring until you get to the problem.

 

Keep in mind that fuses can visually look good and still be bad. It doesn’t happen often but it happens. I always verify with a multimeter.

That bottom fuse looks pretty tarnished/corroded and I would probably replace it if it looks like that in person. Sometimes you can clean them up with a pencil eraser.

Did you check the the output pin on the truck with a multimeter or test light to verify that the signal is or isn’t there? If he plugged it in upside down and forced it like most guys will it could be as simple as a bent pin

Bob

 

Thank you both! Haven't yet checked it with a multimeter. It honestly escaped me. At first, I thought the blame was my cargo trailer (1989), or dad's gooseneck being kind of.... "different." It wasn't until I hooked up to the Sundowner that I recalled the upside down plugging in incident. Boyfriend tested the trailer earlier this week and that was fine, so it's a matter of finding out what the truck wants now.