Air con is working blowing out of all vents except the two on.the dashboard
 

Hi my air con is working fine and comes out of all vents except the two on.the dashboard and won't clear the windscreen you can hear the blower working but no air is coming out of the vents on the top.of the dashboard on my A4.be grateful for your help thanks

The most common problems that cause a lack of airflow include frozen coils, broken fan and restricted airflow due to dirty air filters or vent obstruction. Try check it