OK, sorry, I am still trying to figure out how this website works.
I tried what you said and the temperature for the evaporator bottomed out at 25 then started climbing again. It did not get down to 20. What are the chances that the sensor in the feedback loop that tells the compressor when to turn off is bad. (I bought the schematics years ago when this started occurring). I seem to recall that the problem showed up after an electrical storm. I know that freon is the easy answer but....Would it be worth it to install a new electronics panel? On the freon side is it possible to have a small leak that is 5 years in the making until it makes itself felt?
>>>On the freon side is it possible to have a small leak that is 5 years in the making until it makes itself felt?
Yes, absolutely, You can test the thermistors if you like. Remove the ref shelves and the light difuser. You will see three (or maybe four) screws which attach the rear panel, remove them and pull the top of the panel forward and lift the panel up and out. The thermistors have two royal blue wires about 6" long, unplug them and remove. Put the bit in a glass of mostly ice water for at least two minutes and take a resistance reading, it should be around 10,000 ohms +or- 500 ohms. The wiring harness connectors often get corroded but then the display will flash "vacuum condenser" and it will not give a temperature in diagnostic mode but will say "EE".
I really don't think a thermistor or control board is your problem. While you are testing the thermistors it will be a good opportunity to check the frost pattern on the ref evap coil. If the coil has only the top one or two segments frosted then we can be assured the problem is a refrigerant issue. If there was a leak and it was not repaired but merely refilled of course it will leak again.
Just wanted to let you know that the thermisters checked out, unfortunately. It would have been easier if it was an electrical problem!
I have a friend who should have a device I can use to read the pressures, but you are right in that there is probably a small leak. The trick now is to find it and not just pay (again) to get the freon recharged. Bummer!
Thanks for all of your help!
I told you. Just don't let anyone put in anything but virgin (non-recycled) R-134a refrigerant.
PS I told you so.