Kenmore Coldpoint Cools then stops

I have a Kenmore Coldpoint Side by Side Model 106.59429801 manufacture date of 7-2009. It will cool to temp then stop. I hear a fan, but don’t know which. I unplug the fridge, leave it off for 30 seconds, then plug it back up and I can hear the compressor and fans kick on and run and the fridge gets nice and cold! Then it hits temp again and compressor and fans kick off, and then some time later all I hear is the fan come on and the fridge begins heats up… This is the ugly cycle I am in.

My wife, who is working in grocery retail and dealing with their freezers, says it may be the thermostat because it sounds like it is stuck in defrost mode. I have done some internet research and I think it is the relay switch on the compresor, but then again, that is why I am asking for advice. I have not replaced any parts yet as I don’t have a clue where to start.

I am NOT an experienced appliance repairman, but I am technically savvy as having repaired cellular phones for 5 years, so I am comfortable with everything except coolant replacement.

OK, here’s a few tricks I use to tell what part I need; Next time it stops cooling, open the door to the fresh food section and “smack” the cold control on the knob with your hand. If the unit turns on, replace the cold control. Unplug the machine. Remove the start device from the side of the compressor. It pulls straight off but you might have to remove a bail wire first. Shake it and if it rattles it’s bad. Replace it.

Check the compressor in the back, it might be overheating due to clogged condenser coils, or a bad condensing fan motor.