Okay, here's what happened going home tonight. When I turn the truck lights on the trailer lights come on. When I hit the brakes, the rear trailer lights go out. When I hit a turn signal or the flashers the rear light/lights go on and off, not on and then get brighter. I have a 01'Dodge with the factory trailer plug that the boat trailer light plug plugs into. Did that make sense?

In other words, the factory plug can only plug in one way because of the little rectangle "key" and the trailer lights can only plug into it one way because of the typical I male/3 female "contacts".

With the truck lights off, when I hit the brakes, turn on a turn signal, or hazard, nothing.

Any guesses?

I hate electrics.........

Sounds like the ground is reversed somewhere. Its not hard, but I think you are going to have to stick the a meter on the plug on the truck, and make a harness; or did this JUST start happening?

You may just have a bad ground OR if you have changed lights recently make sure you did not put them in wrong or put the wrong bulbs in.

Jon

I had the same problem with an old trailer. I redid all the grounds. If you installed new lights make sure they are grounded properly.

Sounds to me that you have a couple of blown bulbs. They are double element and will show running lights but no turn or brake lights. Check the bulbs first then the grounds

get a dog like mine, then you wont have any lights to worry about

Sounds like a bad ground or just bad connections. I solder and shrink tube everything. If you have the crimp type connectors on the trailer, that would be the first place to look.

Definatley a bad ground. If the wiring on the trailer is old and crapy don't even mess with trying to find the bad ground. Rip all the wiring off and start from scratch. I know it sounds crazy, but in the long run it will save you alot of headaches.

What he said!

Sounds like they are operating properly. I think that trailers are shipped from the factory with lights like that!