I just purchased a 2013 Tiffin Allegro Red with 16,000 miles. The person that sold it hardly drove it. When I picked the coach up at the dealership it was plugged in and everything working in properly. I brought my coach home and everyone I plug into shoreline there is a thumping from trc surge box in the storage shoreline cabinet. I unplug and turn on the generator and everything is normal. I have checked my electrical box and everything seems normal there. I checked power at the shore box with approx 115 on each side.
The only abnormal wiring I have found in my electrical service box is that there is no separate neutral wiring, neutral is wired with ground.