Cools on Propane and 12V, but not AC. AC worked to cool it down in the driveway on Thursday, but camping over the weekend, I was plugged into AC and noticed the fridge was getting warm inside come Saturday late morning, with food that was cold from night before (like a gallon of milk for the kids). Switched to propane and it got real cold. Confirmed power at the dedicated outlet, so it's not the converter, a breaker, etc. I'm handy with a multi meter, so what can I check for continuity, voltage, etc? Thermostat? Is there a limit switch? Heating element leads? It's in a 2015 Rockwood Freedom 8 foot 1640LTD. Thanks in advance.