My Kenmore refrigerator (refrig only) 253.6072200, suddenly stated to freeze its contents. I put a max/min, wired probe, thermometer in it to monitor. It seems to spend most of its time at -25 C but warms up to 3 C at some points. There are snapping noises coming from somewhere near the compressor at times. Where should I start to troubleshoot?

Thanks

Forgive me if this is a dumb question. Why would the temp go up to near freezing if the t-stat was bad? Note that the probe for the remote thermometer is enclosed in a contraption that has some thermal inertia.

Here is another way to ask my previous question. Is this a simple, snap-action thermostat? If so, how could it fail in a manner so that sometimes the temperature is -25 C and sometimes around zero C (freezing temp)?

I understand how the t-stat might close and keep the compressor running until a pressure switch turns it off, but I would think the temp would be consistently lower in that case.

Is the t-stat the only thing that could fail and drive the temp too low or could it be something else like a sticky relay?