Here we go again yet another Trombetta "Big Boy" failure!

Electrical is not my strong point. I look at the wiring in my RV which I assume is rather typical.

I would not try to start my RV with the house batteries, the wiring and circuit breakers are too small.

My class A was set up with high amp breakers and large wires, heavy duty selector switch so was able to start with house batteries if needed.