Exterior Lights?????

[tjconcord]

Wired in new plug on trailer. Brake & Turn signals work when plugged into vehicle. Running lites will not work. Tested plug on truck (top left tab) has power. Running lites wired to same spot on trailer plug. Hook 12 v to trailer wire for running lites all work(marker and tail). Plug into truck no running lites?? Can anybody help?

[Gone Kayaking]

I'd guess that you may have a short somewhere in the wiring for the running lights, harness to the truck or there may be a very weak ground that needs to be strengthened. Make sure all lights are well grounded to the frame.

This is the bain of many of us....took me 2 days of finagling to get mine to work. Patience grasshopper.

[vikx]

If the trailer is testing good, either the truck has a problem or your grounds are not making good contact. Good luck and let us know.