1. Have you Confirmed it's not charging at all? (IE Have you checked that you have 12V at the trailer plug?) Dodges don't need an extra fuse.
2. Confirm that current is getting to the battery?
-There is a high likelihood that it IS charging, but your vehicle 12V hot pin is not capable of carrying high amps.
- When your battery gets low, the fridge shuts off, whether on LP or DC.
How quickly depends on which mode you're running. LP only draws a few amps, DC mode = maybe 4hours out of 1 fully charged typ 12V battery, tops.
