I know someone can help me out with this even though it is in regards to a used trailer I bought to pull with my truck. I painted it and put a light kit on it. Everything is wired properly as I triple checked it yet all the lights (side marker and stop) come on when I step on the brakes. They also all light up when I turn the headlights on but then they all go out when I step on the brakes. I attached the ground to the frame of the trailer but it is on the freshly painted surface. Do I need to get the ground down to bare metal? Are these symptoms of a bad ground?

Thanks

You should run the grounds directly to the trailer plug, not to it's frame.

The plug that came with the light kit had 5 wires coming out of it.....4 to the lights and one ground wire (white) which was short and the directions said to connect it to a ground location on the trailer which I did. If the ground is bad would it cause those symptoms?

Maybe so, weird things happen when a voltage is induced from one bulb filament to the other and it feeds back.

Using the trailer's frame for a common ground is OK IF the white wire is has a good connection on trailer frame AND on the tow vehicle frame plus good ground connections at each individual light.

All connections to the frame need to be on bare metal and really should have a light coat of dielectric grease to prevent corrosion.

I prefer running a ground wire rather than have a bunch of individual frame grounds to corrode, myself.

Thanks Dean. I checked the ground on the truck plug and it looks like someone grounded it to the frame of the truck as well! I'm going to use your advice and do some rewiring for sure. Thanks again.