GFCI trips when Norcold N641 on AC. Only have 4 days to fix

I knew more gremlins would try and spoil my trip in less than a week.

My GFI is tripping when I run my norcold N641 on AC. I don't have a ice maker.

So I assume its the heating element? How do I test it, or any other tips? I sure hope the LP side works, or I'm hosed once again.

Thanks!