I have a KitchenAid KSSP48QHB00 built in refrigerator and the evaporator fan freezes ,when it stops blowing I take the panel off to access it and it will usually start blowing before I get the cover off because it thaws out but if I’m quick I can see the motor slowly turning and soon as I get the cover off I can see a hint of ice blow off and then it runs at full speed again
It has new compressor and evaporated line
Replace fan motor twice
I manually turned the timer to defrost mode and the heater came on (burnt myself) it went over 450 degrees measuring with a meat thermometer
Another company supposably rebuilt the computer board (still did the same thing )
New main switch

Any ideas on where to go from here?
Thanks in advance