With a used RV I always remember it wasn't sold because the previous owners loved it and couldn't stand to part with it.
When alternator inventory was filled, and battery tests were well underway I worked on RV's. Almost without exception, newly purchased used RV's came with a host of land mines. Anyone who'd believe such land mines had nothing to do with the previous owner selling the rig would have to be Mr. Gullible Inc.
Electrical faults may be the # 1 reason RV's are led to the auction block.
When I did more than a minor repair to a Rig I would spend ten minutes with clipboard, and printed check out sheet listing the faults I observed. A good eye catches faults like raw hamburger and soda attracts yellow-jackets.
A cordless screwdriver was used to open up the breaker panel. An overwhelming amount of the time I found loose set screws, burned wire ends. Even though the original repair did not encompass faults, I made the owner sign an "exception" proving the fault was pointed out to them. Not every RV owner is a Boy Scout and doing this prevented many a lawsuit court defense. A few owners got madder than hell when faults were pointed out to them. Good riddance. This was a great filter. Let them go "con" someone else.