DM-----------WHAT?
Thermistor would be at end of 2 wires that come thru liner on right side of back wall in food section of fridge.
All Dometic full size RV fridges have them.
Unless you have a small compact type rv fridge with knob controls.
SO.......did you look for the data plate on inside of fridge or on backside for the model number?
What RV is this fridge in?