Howdy, I have an interesting problem, which I at least know the symptom, trying to figure out the cause.
Basically freezer is always cold, fridge intermittently warm, due to no air flowing through damper.
The culprit is the evaporator fan. I took the screws off back panel for quick access to see what it was doing when fridge was warm. Basically the fan is spinning too slowly. When I open freezer door and remove back panel, after watching it for 30 seconds to a minute, it speeds back, and if I put the panel back on, it will blow cold air into fridge and cool it down, but then within 24 hours, it will slow down again.
During the troubleshooting I also believe the temperature control is faulty, and driving compressor to run continuously. Would it be possible fan getting too cold and not spinning correctly, then when I open door it warms enough to run quicker? (I'm assuming these are fixed speed fans) I did replace the evap fan about 4 months ago due to noisy operation, this issue started shortly after that, (bad fan?)
I believe that the defrost circuit is working. After drying the drip pan and then advancing the timer to the defrost cycle, I will have water in the pan.
The temperature controls do not seem to be affecting temperature or compressor operation. If I understand this correctly, the temp knob in freezer controls compressor operation, and temp knob in fridge generally controls damper door.
If I pinch the thermistor in fridge to heat it, the resistance will smoothly change from roughly 4.1 kohms to 2.7 kohms. I cannot find the info on what the values should be, but it does change smoothly. Neither heating this nor adjusting temp knob changes damper position. (It is currently always open) If I disconnect the thermistor, the damper will close. Re-connect it, full open.
If I turn the knob in the freezer to the warmest setting, the compressor remains running. It seems to only turn off during defrost.
Other troubleshooting:
Defrost thermostat (temperature switch) seems to work. If I put it in freezer, I get continuity across wires. Take it out and heat, it goes open.
Defrost heater wires have continuity across them
Defrost thermostat seems to work (cuts compressor, then back on after 30ish minutes with water in drip pan)
Return path for air to freezer is not clogged
So I think my compressor is always on, then something (too cold? frost?) causes evap fan to slow down, air does not move into fridge, and gets warm, eventually it will cool down again, (possibly defrost cycling heating fan), then it follow this cycle over and over
Once I realized the fan was changing speeds (again, assuming these are not variable speed fans), each time the fridge was warm, if I open freezer door and back panel, within one minute, fan speeds up and fridge cools.
Also, temperature rheostats in freezer and fridge appear to not control temperature at all, nor ever turn compressor off in freezer knob's case.
Did I get a bad fan, or is that a symptom of a larger problem with temperature control?
thanks
Ken
