Is the Trailer plugged into the Garage via an adapter or JUST the Fridge (Yes folks that is possible)
DC means the trailer batteries.. Normally they charge from "Shore power" (The garage) via a device called a converter.
Suspect list
Garage power.. Is the outlet live? Use a test light
RV: Circuit breakers.. Is power reaching them.. IF YOU KNOW HOW use a test light or volt meter
Is the breaker for CONV tripped, or the main
The converter.. IS IT CONVERTING? Use volt meter on output terminals, disconnect battery and give us voltages both batteries conencted and disconneted
Blown fuse (Converter, Fuse panel, Battery main circuit breaker (usually near battery)
FInally...... If you only plugged in the Fridge by an extension cord.. Plug in the entire RV wait 2-4 hours and try again.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times