Amana Refrigerator Freezer Issues

Amana BR22 refrigerator freezer has been freezing up for the last few weeks. I turned off the freezer using the off switch in the freezer, removed the back panel and using a blow dryer melted ice off the coils and all ice visible. Turned it back on and everything was great for a few weeks and now more ice. Did the same procedure as before but now when I turn it back on the fan is not working in the freezer. It was working when I turned it off. I have ordered a new deforst timer and defrost thermostat. Now I am wondering why the fan stopped working, does this mean I need to buy a new evaporation fan motor.

Any thoughts on why it would just stop working since it was working fine?