Weird fridge issue

[vtchris]

Why would my RV fridge Dometic 2410 work perfectly on propane and then freeze my veggies and go down to 20 on electric? Readjusting the thermostat doesn't make a difference. Plus it takes 2 days for this to happen. The fridge is just 4 years old and up till now has worked perfectly on the 3 setting and I often switched back and forth from propane to electric (no DC setting), being a full timer it has had a lot of use!

[Old-Biscuit]

Your fridge has simple controls....no electronics/no control modules/no circuit boards.
Just ON/OFF-----GAS/Electric Thermostat----Piezo Lighter

Sounds like thermostat is not turning electric element off ----allowing it to run continuously

Thermostat should turn element ON/OFF when temp set point is reached.
In gas mode it would shut down gas valve and go to bypass when temp set point reached then increase flame as fridge temp increases.

Check selector switch continuity
With AC wires removed......and AC Selected
Continuity between 4L and 4A
Continuity between 5N and 5A

Then Check thermostat continuity

[MrWizard]

Simple
The electric heating element is providing for energy than the burner does
Try cleaning and adjusting burner
As too why it does not respond to the control knob
You might need a new control board