Ok, well I am now at the point I would like to see the thing burn down and get a new one.
I put all the GFCI's back together in the trailer. No issues.
I unplugged the converter. No change (still blows the GFCI in the garage).
I plugged a fan into the converter outlet (that the converter was plugged into). Outlet works fine.
I completely removed the converter. No change.
I turned off all trailer breakers. Turn on main breaker. Ok.
Turn on a single breaker for the rear of the coach. Stereo comes on ok. TV light is on. Turn on TV. Blows GFCI in garage.
Repeat turning on the front of the coach, TV in front on standby ok. Turn on that TV. Blows GFCI in garage.
I have 3 individual 20 amp breakers in the garage each to their own GFCI outlet. Changing to a different one makes no difference.
Plugged the trailer into a non GFCI outlet on the front of the house (runs to the basement). Everything works without blowing the basement breaker. I turned on, plugged in every 110 operated item in the trailer. According to the panel, I am pulling 4 amps and about 115 volts on each (2) circuit.
Well not everything. It appears in this BS, the Norcold fridge got fried as I get a LI-op error whether on AC or Gas. And I know it was working (heard the gas running) when we got home from Ludington, before I plugged in.
I am at a loss.