Coolmatic fridge wont get cold on batteries

[searay495]

Hi everyone, I have a 2003 340 Sundancer with a coolmatic fridge in the cabin. It will get cold on generator or while plugged in, but not on battery power. Any suggestions? Thanks in advance, Mark

 

[GrandMaster]

Does it turn on when running on 12V and just not get cold, or does it not run at all on 12V?

Have to ask, it is a dual voltage unit correct?