M_Boats: boat light question

Pin is in; hope it holds. (It should as there is no real stress on it and I won't be doing miles of driving anymore.) Trailer lights are out. One is really weird- the bulb was fogged sort of an off-white. Replaced it and the new one fogged the same way immediately. What's wrong here? Turn signal and brake lights are the ones not working; power gets to the wiring harness but not to the bulbs; we're going to go ahead and replace the lights I think as they are quite old. Bobbie