The alarm is probably your LP gas detector. It goes off when the battery gets low. When you drive, the alternator is charging the battery and the alarm goes off.
As for the refrigerator, it sounds like you might have an electrical connection problem or a circuit breaker might have tripped. Will it work on gas mode?
You can open the cabinet to the refrigerator on the outside and unplug it. Then plug in a light or other electrical device to see if you have electricity to the outlet the refrigerator normally plugs into. If not, you can start tracing where the electricity problem might be?