^^JR...no sense to dig a deeper hole, just reread my last two posts. You were correct, you have no idea, nor do I on the info given.
Now you asked me to explain my earlier reply. I did...you still are not comprehending what I said. "Even a light touch to the BRAKE PEDAL", can cause the issue I described.
You obviously have never replaced wiring inside the axle tube, when needed. The chafing to wire inside, leaving lots of bare wire, will shock you! I have BTDT, so I'm speaking of personal experience. Have owned 4 RVs, and a dozen other type trailers.
Trailer lights are an easy fix, for anyone that can understand what is normally a simple ground problem. Anyone can service a couple slow moving, small, lawn equipment trailers.
BTW...your house payments must be really small, that you can make them, by helping someone get their trailer lights working. That is good, if you are not taking advantage of friends or relatives by overcharging.
Now, we will wait for further info from OP, unless YOU have another question, but best not to hijack the thread at this point!
Jerry