What Voltage is your Trailer At?

[rsinger]

It could be a floating ground but i am checking the + AND - of the wires going to the lights. Only reason i can think of a floating ground is if the trailer is actually grounding through the hitch on the truck.

I had the lights pluged into the truck but not the hitch

Someone can correct me if I'm wrong, but I think one of the connector leads pushes the ground through to the trailer. Then on the trailer end that same lead will eventually connect to the trailer frame, which is used as ground and one terminal of each light fixture connects there. So even with the hitch not connected the appropriate voltages should be found on the trailer.