the lights quit working on my trailor I have checked fuses in fuse box under dash and under the hood all fuses are good. Is there a relay???????
Please help!

 

Do you have a continuity tester to make sure you have juice at your trailer plug? If not you can get a little inexpensive one for this almost anywhere.

Do you have a good ground connection?

Do all the bulbs work?

Are there any loose wires anywhere that you can just jiggle and lights go on and off?

It might be a fuse (unless you have power at your plug), but it could also be something very simple that still can drive you NUTS trying to find it.

 

the bulbs are good
no loose wires
there is no power to the plug

 

I'm out - I know how it works on the trailer side, but I often get totally lost when working with stuff like this on the truck side.

Whenever I do work stuff like this I look for the simplest problems and eliminate them first and that was what I was suggesting to you. If you have no power to any contact in the plug it will most likely be something common to all of them.

Good luck - I KNOW there is someone here who can help you figure it out.

 

I had the same problem on a boat trailer once. I tried the fuses, new plug on truck side and the boat side and it still didn't get the lights working. I had to pull the whole wiring harness from the trailer and found that it was two harnesses connected together in the middle of the trailer frame and did have bad connections. I replaced the whole wiring harness and never had another problem.

 

How do the contacts on the plug look? No power before the plug, or coming out of the plug? Check to see if it has power at the fuse then work your way back.

 

Which lights failed- running or turn/brake, or ALL of them?

Did they previously work? If they never worked, see if the relays were installed.

If all have quit in all functions, suspect an open ground, it's the only thing common to all functions.

If running lamps failed, running lamp relay or fues F1 in the Power Distribution box.

If both brake/turn signals, check fuse F2 in the small fuse panel located in the corner of the firewall and the fenderwell.