My Winnebago View had a radio power selector switch to operate off the chassis, or the coach. The problem was that it, of course, had an aftermarket radio in it, which in itself was crappy, and WBO failed to provide power for the memory circuit.
Basically they had made a T shaped wiring harness that plugged into the Dodge/Mercedes harness and into the radio and then had a leg that ran off down to the selector switch on the lower left of the dash.
Even if they had provided a DPDT switch to switch over both the main power and the memory power, which they didn't, you would still interrupt the memory for a split second and lose everything anyhow. If they took the memory straight thru from chassis to radio, then there would be a drain on the chassis by the memory.
End result was that you started up the vehicle and let it find a station, set the time, and when you shut it off, you lost everything. Similarly, if the radio was on coach power, and you manually switched the radio off, you still lost everything.
I got so mad at the whole thing that I removed the radio and the wiring harness and threw it in a box. The Mercedes blanking plate for the radio opening was in the glove box, the factory was rather thoughtful and didn't throw it away. I don't listen to the radio anyhow, but didn't like it flashing the incorrect time at me while I was driving. So the whole time I had it, there was no radio.
Before I sold it, I found someone on Ebay with a batch of brand new Sprinter AM/FM/CD players that were a perfect fit and worked perfectly for a measly $100. All I had to add was a antenna adapter to take the US antenna coax to the European radio.
Long story, but yes, Winnebago does screw things up too. Later models just had a separate radio in the coach.
Charles