Took out my 2008 Tiffin TGA yesterday and while at a site put the generator on. As my wifes portable fan was blowing, all of a sudden it stopped. I then checked a couple of outlets and no power. Went out to the Onan 5500 Marquis and noticed one of the switches was off. Turned back on, and within a couple of minutes it shut down again. Any idea as to what is causing this. I checked the filter to make sure it was getting enough air and it was pretty clean. It was the white 20 amp that kept shutting down.