my refrierator is not getting cold, the fan in the freezer is blowing ice cold. the air diffuser assy had some ice in it. I melted the ice and it is clear now. my question is does the air diffuser assy have a little motor in it that is to help blow from the freezer to the refrigerator, if so mine does not blow. should I replace the air diffuser assy your part # AP3084126? is this common part to go bad and what causes it?

Thanks for your help

Rusty