Hi, The schematic diagram you sent about the A/B switch made me think. So I checked your other posts and I think we have a lot in common. Maybe can help each other.
I have a 2004 35' GS Independence. It had 4k miles on it when I bought it in 2018. It had leaked badly. I replace the entire floor all the way from the frame up. Sanded one side thick plywood. Linoleum square tiles in from, maple wood in rear.
Being an electircal and electronics guy I saw it was wired by whoever was at work that day. There was no schematic of the over all coach wiring. Do you know where to find one?
Regards,
Steve