My experience with motorhomes , regardless of the manufacturer, is that wiring diagrams tend to be basic for that particular coach and often they leave out any additional wiring they may have done. A friend has a Monaco and we could not find a 12v fuse that controlled the window shades. The shades were an optional feature at that time and the fuse panel was in the closet. The list goes on and on. Even Prevost, worked on a few of those also.
As was mentioned, isolate each project and ask questions. Once you do that it's easier to understand how these were built.
