Western wilderness refrigerator issue

[David_costan7]

Hey everybody,
First time posting on here. NOT my first time coming here for help. I have a 1991 western wilderness 10’ alpine series truck camper. Fairly new to me and I’m fixing things as I can.
The issue I currently have is with the refrigerator, Dometic rm2510. The refrigerator works on both electric and gas operations. The thermostat will only turn up to 5 (7 and Max are the highest). I tried turning it up further and heard the plastic rod end that connects the thermostat knob to the thermostat *snap*. What would cause the thermostat to seemingly seize? Anything I can do to free it up? Or do I just need to replace it.
Thanks in advance! This is all new to me.

[MrWizard]

What happens when you turn the temp all the way down ?
Is the knob in the correct position ?
It is it on '3' when it should be on '1'
Maybe everything is working and it's just a knob & shaft position issue
Does the fridge get cold enough ?