Refrigerator Garage Heater Kit for Frigidaire Kenmore Refrigerator 5303918301 AP3722172 PS900213 AH900213

I am the OP and apologize for still not having gotten photos of the evaporator. I am having difficulty arranging alternative storage for the stuff I must remove. Perhaps later today... Meanwhile, perhaps a few more observations: I mentioned in earlier comment (not the OP) that in 2022 I had installed a garage heater kit in this machine along with an indicator LED and a toggle switch. At the same time, I installed new defrost timer, defrost sensor, and temp control. These have all been working, seemingly just fine, since that time. But I have not had a temp sensor in the fridge box until earlier this year - only in the freezer. So I cannot be 100% sure. When I first started noticing this strange temperature behavior around mid-May, I had recently turned the heater kit OFF since it is not needed when the garage temps (which I also monitor) are higher. This has been usual for me since it was installed in 2022 and I have never seen any side-effects of doing so. In my recent testing, I tried turning the temp control full-on (coldest) to see if that had any effect. It did and things got cooler. In the freezer much cooler but also some temp decline in the fridge box. As a result, however, the unit ended up running constantly for several hours - which I understand is not expected or good for the unit. I turned the temp control down one "notch" (4 out of 5, as I recall) and, as expected, temps did start to rise again. But the unit immediately stopped running constantly. I decided to then turn the heater kit switch back on to see what happened. At that moment, the unit was not running. But as soon as I flipped the switch, it started up immediately and illuminated the LED indicating that power was going to the heater. After having done this yesterday, the behavior of the unit has been fairly "normal" with fridge/freezer temps staying fairly constant at 38/0. And the unit is NOT running constantly. It runs for about 30 minutes followed by about 1 hour off. I am not sure how "normal" this is. But I can readily see the changes in current being pulled. I have monitored the feel of the plastic housing that contains the heater. It never gets really warm/hot but I can definitely tell when the heater is on (as indicated by the LED as well) and off. So I do not think there is some run-away heater problem - although I have read about them occurring sometimes. Everything else seems "normal" enough. The timer is rotating as expected. I see no frost or signs of moisture anywhere. The temps of both the compressor and the condenser have remained about the same when the unit is running (105/95) I have seen the current jump from 1.2 amps to over 3 amps one time for a period of 10-15 minutes before falling back to 0.02 amps or so. I am presuming this was the defrost heater going to work. So far, my monitoring - which was disturbed overnight by a computer reboot - has not show this again. If so, given the fairly short time involved, it would seem that the defrost sensor is at least preventing a run-away defrost cycle. All of this makes me wonder about the temp control unit. After all, it is the component most affected, I think, by the heater being put into/out of service. Also, when set to the maximum (coldest) the unit ran constantly - apparently never satisfying the temp control unit's demand - which seemed strange (however, I do not know what the target temp of this setting might be). Is this a possible theory of the problem? Is it possible to test the temp control unit somehow? I have a basic volt meter. Thanks!