Hello,
I have a Kenmore upright freezer in my basement (model: 253.22042410) that is exhibiting a cycle of interesting behavior. It will warm up to just about or above freezing (32-38F) over a series of hours, then run continuously until the temp dropped to about -10F. Then repeat this every day or see (See image provided from my temperature monitoring app)

1. Visually confirm if the Evaporator coils inside the freezer are frosted over (Likely a sign of the Defrost heater or timer not working)
a. Lite but even frosting across the whole coil after running for hours.
2. Test the Defrost heater for continuity. If is does not, this could be the cause.
a. Confirmed to have continuity
3. Test Thermostat’s thermistor for continuity
a. Confirmed to have continuity. (0.0 resistance even with hand on metal tube.)

What could be the root cause of this issue?
1.) Relay?
2.) Capacitor?
3.) Defrost timer? (I see this rotating over time, and I have not yet seen an iced up evaporator coil.)
[img=https://imgur.com/a/rduOiWV]Freezer Cooling history[/img]

Did you ever resolve the problem?, I am having almost identical problem....