I have a 1999 Newmar Mountain Aire with an Onan 5500 generator that will not pull the relay in after I start it. This only happens occaisionally. I took it to Cunnins to service it about 2 years and they said it had the wrong plugs in it at that time and changed them. The relay at the transfer box didn't have any voltage reading when I checked it. I turned the generator off and on a couple of times end then it worked. I think it is a simple fix but don't know what to check. Your input would be greatly appreciated.