as a followup to my previous comments.
I have a dometic RM4862 propane/electric
in a Rear Kitchen 2007 3000RK Montana.
https://www.dinosaurelectronics.com/Dom_boards.htm
The Dinosaur control board was an improvement over the dometic and includes a adjustable rheostat on the control board separate from the internal fridge thermister.
I installed the Titan dual 12volt rack fans at the roof line slightly below the vent.
They are designed for refer external cooling/venting.
avail at amazon in a couple diff sizes. I purchased the 140MM
it includes a thermostat and adjustable speed controller.
The combination has greatly improved the refer/freezer operations.
i consider The Exhaust fans a critical upgrade.