Follow-up on refrigerator temp problem

First I wanna thank everybody for the great information you provided. I started with the simplest solution first the wire for the thermistor was not long enough inside of the refrigerator to get it to its highest position I went in the back of the excess and loosened up some more of the cable pulled it through the refrigerator and put the thermistor higher up on the metal fins I checked the temperature after eight hours and it was at 34 to 35° this afternoon I went in and checked it and it’s maintaining the 34 to 35° so problem solved thermistor was not high enough on the fins in order to maintain the temperature below 40° again thanks everybody