anyone out there a wiring pro for trailer lights???
My brake lights work, as well as the turn signals. The running lights don't. I know I have to connect the ground to the trlr. frame and check the bulbs ..I did that..no result...What else should I check???

try using a volt meter. pull the bulb, and see if you get any volts. if not, make sure the connections are clean, and then trace all the way back to where the trailer plugs into your car. i had a similar problem, just needed a new adapter that plugs into my car.

That was my problem this spring, turned out to be a bad wire inside the trailer tubing, which I eliminated for good by running all the wiring on the outside of the trailer. Now it's all visible and a simple matter of checking connections, yeah it's not pretty but I've never been too concerned about looks:).