Thanks, Dan and Brian. I checked and do have a good ground. I have not installed a converter/ isolator. I do have a combination of both LED and incandescent lights on my motorcycle and on my trailer. I am considering changing my complete harness to a 5 wire so that I can use my LED, universal light bars' brake light, that I installed on my trailer, and got from signaldynamics.com, along with the standard incandescent tail, turn, brake, and marker lights that came with the harbor freight trailer.
Do you think that will do the trick without the motoleather.com universal isolator harness? Thanks again.
/Charlie (old salt)