AC power module?

What is your question?

My air conditioner is working correctly but the direction of the vents is not. I am getting no air flow thru the front/dash air vents. The floor board are blowing and the rear car vents are blowing. I took my car to a local shop and they said it was the "AC fan control unit or power module". Are they right? And what is the average cost of this part? They want to charge me $530. Can I replace it myself after purchasing the part from the dealership? Thanks, Jillian Solom