Is this thing supposed to operate on 12V and 115V? Mine was "unplugged" from the 115V socket, so I plugged it in, and it still does not operate except from 12V. Maybe I've got a bad socket or circuit breaker.

I think it always runs on 12 volt DC. When you plug in shore power, the 112 AC is converted to DC.

Yep, mine works the same as Troutly's Turn the DC off plug in your AC then turn on the ac circuit breaker for the fridge.

Same with mine.
Off the DC breaker
On the AC breaker

It seems like if there is 115VAC, then it should automatically drop the 12VDC operation. I still have not had a chance to check the 115VAC to see if it is actually there or not. I'll be checking tomorrow.

I think mine works on what ever breaker is on. I haven't got the balls to turn them both on at the same time...maybe it will get twice as cold

Reading the manual says that if AC is present, it won't use the DC power. I measured the socket and there is NO power with the breaker on, and thr fridge works on AC from another socket. So.......just have to see if the breaker is bad, or a broken wire some place.

Check behind the socket the wire may have vibrated loose.

Nort,
Did you plug in the BIG yellow wire first

What BIG yellow wire?