Every other trailer I pull...

[Rockhwy]

I have had similar problems with lights on the trailers I pull, I do a lot of drop and hooks sometimes up to 4 or 5 per day and it would wear light cord plug and would not make good contact, replaced a lot of plug inserts . I bought a Grote ultra link light cord and no led with wearing out plug for about 2 years now. Years ago it was quite common to have fifth wheel ground wire to frame but back then every light was a incandescent bulb in a socket they would corrode easily shake loose draw a lot of amps. Lights have come along way since then.