2002 C320 - Auto climate

I have no airflow(heat) from drivers side footwell area. Clicking sound for about 1 minute after starting the car. I verified clicking is from the lower plenum "flapper" that opens and closes the airflow to the footwell area. Snaps open and closed a bunch, then just closes. The rest of the heating funtions are fine.

Any ideas on what the problem is?

Thanks,
Brian