Monaco got pretty creative routing wires where they were needed. Really only way to know what's going on is to trace the wires. A good Fox & Hound will help at it will provide a signal as you trace the wire
https://www.amazon.com/s?k=fox+and+h..._ts-doa-p_1_12
Spend the money and get a good one, I needed one fast ~3 years ago and bought one from Harbor Freight, it kinda works but not great. It does provide a signal but have to be pretty close to the wire to pick up a signal.
The power starts at the fuse panel. It could be either the (+) or (-) wire. Start at the switch and see if you can trace the wire to where you loose a signal and then you'll have to find the wire.
Wiring looms run in the ceiling but go up/down as needed for the different locations.
All my overhead cabinets have false floors that wires are run through
Behind my refrigerator was a mass of wires.
Each windshield pillar has wires.
I had a bad circuit in the bedroom, it worked fine on shore power but the generator wouldn't run with that one breaker on. Used the wire tracer and determined the problem was in the ceiling, I'm pretty sure mice or squirrel chewed the wire and there was a minor short causing generator not to run. Figured out a way to reroute wires, this was not an easy fix, I had to completely remove the main breaker box to get at the wires and gain the ability to reroute wires. Took several days to diagnose and fix. No telling what a shop would have charged to do this.