Hi,
I have a Whirlpool "top/bottom" refrigerator which is less than two years old. The fan motor's perm. magnet rotor, which is of a power iron type of composition, had a piece break off and fragmented. The fragments "jammed" the motor. I used a shop vac to suck the pieces from the rotor and stator assembly. Afterwards, the motor ran. I installed the motor, but I ordered a new motor. I hope that the new motor will be a better quality, made in America motor. Note: This fan is located in the back of the freezer compartment.
If you have a Whirlpool "fridge", when your fridge is "running", make sure the fan is also running. My fridge compartment temp rose to around 54 degrees due to the fan not running. I had to throw out a lot of food.
John