Trying to plug into shore power, popping house GFI

[MudDog]

Sounds like you had the refridgerator fan on.

When the TM is folded down, the heat from the fridge (when on) can't escape out the normal vents, so if you need to run the fridge while you are in transit, you need to run the fan which draws the heat down and out the bottom.

The "Refridgerator Fan" switch is on the status panel under the sink.

You may also want to check the knob on the 3 way switch. There are 4 positions - off, gas/LP, battery, and electric.

Running the fridge on battery will drain the batteries pretty quick unless the batteries are being re-recharged (from the tow vehicle for example).