Tom I am by far not a NorCold pro. When my Norcold started going bad I found one of the problems was the heat safty shut off switch. Not all frigs have them, if you look at the outside maybe you will see a small box roughly 2x2 attached to the cooling coil. If you see the red light remove the cover and with a magnet reset the switch. I had this problem with my 07 norcold. After doing that a few times the frig stopped all together. A couple repair folks told me about the same story and it boiled down to its just old and tired.
I ended up changing out the cooling system with a JC Refrigeration totally 120v unit and could not be happier
https://jc-refrigeration.com/
Good Luck