My deep freezer quit freezing a couple days ago. I was told to go buy a thermostat/cold control. I installed it this morning and it still isn’t freezing. When I am listening to it I can here it cut on runs a few seconds and knocks off. What could be causing this to occur? And how can I fix it?
Check the compressor, if hot and vibrating, and running constantly, you have system problems, refrigerant leak/ damaged compressor.
Here are youtr parts
Parts for GE FCM7DRAWH Freezer - AppliancePartsPros.com
Could be the compressor or the start device.
Below is a link with how to check the compressor.
Note that this is not a definitive test, in other words it will tell you if the compressor is bad but does not tell you that the compressor is good as it may have a winding to winding short or mechanical problems.
How To Fix a Refrigerator - Appliance Repair Guide - ACME HOW TO.com
Unless you can see/hear a problem with the start device there is not a good way to test it so usually you have to buy a new one and give it a try.
Also may be the overload or the capacitor but this is much more unlikely.
I am assuming that this short cycling was your original problem re the compressor is trying to start but for some reason cannot.