OK
In reply to some ... Not really sure how to check some of the things you tell me.
However. 120 volts is OK to the panel
Battery voltage the same either plugged in, or not.
There is NO circuit breaker tripping and all fuses are OK
The bottom line is that everything is OK as long as the battery is connected with the 120 volts connected.
All 12 volt circuits are OK with battery only.
Thanks for the troubleshooting image.
I'll walk through it.
And there's no way the trip is going to be cancelled! There doesn't seem to be anything I won't be able to do in the campground if I have to.