OK

This sounds like a power converter issue, when you plug into your shop, if you have GOOD AC voltage the power converter makes the 12 volts and charges the house battery, when you unplug you are running off of the battery. IF the house battery voltage is low now, I would first check all the fuses inside, you should have a breaker panel with some fuses, next I would look near the battery for an auto breaker, this should be between the converter and battery, normally 18" from the house battery, if you find that check voltage on each side, it should be about the same, if voltage is much higher on the coach side that auto breaker is at fault, beyond that you should be getting good DC voltage from the converter plugged in and it could be at fault. Also some of these fridges are wired to the starting battery to prevent AC ripple so IF everything else is fine and you have good battery voltage let me know.

As far as the converter location it is hard for me to say, some are stand alone units, meaning they plug into an outlet, so make sure you have no breakers or GFI'S tripped, others are wired in directly to the breaker panel... IF you know the make and model of the converter please let me know, plugged in it should be making the DC voltage AND charging the battery... hope this helps, Robert

Auto Breaker....