Okay, some answers to the questions I generated:
1. I am not the original owner, bought this coach this past Tuesday, and from what I can figure, I am owner number 4. Owner #1 was from 1995 to 2008, #2 was from 2008 to approx. 2021, #3 from 2021 to this week. Lots of records from the first 2 owners, looks like things were reasonably well taken care of, and few modifications were done between then and now. IF anything was replaced it was replaced the same as OEM. Previous owner to me did little to nothing, including NOT doing most of what he told me he had, the more I looked and talked to him, the further apart the ends of the string got.
This coach "checked all the boxes" of what we had in mind for a coach, Excellent manufacturer, correct vintage, correct engine, no slides etc ec. We wanted a good solid coach without all the late model bells and whistles.
The price was right enough that I committed the cardinal sin and did not have a professional inspection sheet filled out, I checked that most of the primary systems were in reasonable condition and drove it home.
2. I have nearly 40 years of experience in electronics and mechanical repair and troubleshooting. The first 1/2 of my career was testing and troubleshooting nearly every part of the instrumentation and flight control systems of Boeing airliners. Open the cockpit door of nearly every model Boeing airline built between 1985 and present, I've worked on just about everything you'll see in cockpit, and a large portion of what's in the electronics bay below. The 2nd half of my career has been in maintenance and troubleshooting of all the equipment and process used to build the above electronics. I tell people I fix everything from electric pencil sharpeners to CNC machine tools.
Hence, there's very little in the sub-systems of this coach that I'm unfamiliar with or afraid to work with, however..........One of the major things I have learned in this career is that prior to just diving in, CONSULT THE EXPERTS, the people that you can identify as having direct experience in what you're about to attempt. most of the time this will save you a lot of time and frustration.
SO HERE I AM, and with the diagrams and schematics I;ve been presented with here, I have a pretty good idea of where my problem is gonna be.
3. Inverter is either original, or if it has been replaced it was replaced with the same Freedom 20 that was there originally installed, same with the main transfer switch controlling shore power vs generator.
4. Yes, I have all the original GFCIs, or at least still have GFCIs in all the original positions.
So, taking a look at the schematics provided by Mr Cherry, THANK YOU very much Tom, I have a real suspicion that the top 2 relays in the box beside the breaker panel are not switching, so they are getting full time power from the inverter, AND when the 2 breakers in question are turned on, relays are being fed from 2 sources, which shows up as a short, tripping the breakers.
It may be a bit of time before I get back with a resolution to this issue, I'm headed out to finish rebuilding the front door step(DON'T cover your step with carpet, it holds moisture and turns your step into rust flavored swiss cheese), and finish putting the dash back together after replacing the blower fan and it's resistor, which was a grand task.
THANK YOU all for your assistance, I'm sure I'll be back with more issues.