Wow! I thought we always had entertainment over on the Truck Camper forum. I can now be doubly entertained by paying more attention over here.
Back in 2011 my refrigerator did not work correctly on my new Lance truck camper. I borrowed a part from my 2003 5th wheel refrigerator and it worked as it was designed. The refrigerator was under warranty, but the nearest warranty service center was 90 miles away so I repaired it myself.
Some systems are the same, some are different. There are 5th wheel RVs that have automatic leveling systems. The Cummins diesel in a Freightliner that pulls a large 5th wheel RV is much like the Cummins diesel engine in the Class A.
I suggested over on the truck camper forum that one of the OPs needs to read How to Win Friends and Influence People by Dale Carnegie. He wasn't interested in winning friends, but was sure interested in influencing people. I don't think he read the book.