I looked at the knob first. Saw nothing ( didn't have glasses on).
Called around and found that if it was a control issue, the whole assembly ( fan, heat/cold, and vent ) would have to be replaced at a cost of about $95 ( after market )
Decided to look at the knob again ( thanks JEK3) and did see some cracks on the plastic. Used some pliers and realized that the control part worked.