Re Reading this thread... There is one and only one post that made sense.. I keep wondering, Since when you are not hooked to shore power HOW can that cord possibly heat up, Where was the current source.
Someone noticed and exposed 12 volt isolator relay and the theory that the ground pin on the 50 amp cord came in contact is the ONLY one that makes sense..
I can see no other way this could have happened.
Had the inverter transfer failed, and the shore power/generator transfer been like mine (resting (no power) state is "SHORE") the inverter would have simply shut down before that cord overheated.
ONLY the exposed isolator relay (12 volt) makes sense it's the only thing in an RV that carries that kind of current.
Home is where I park it!