Air condition fan on 2003 Cadillac DeVille DTS

Air condition working but making loud air blow hard and blow air only on the legs cannot switch the blower to blow on the face or on the window.

Asked by for the 2003 Cadillac DeVille DTS
There is a problem with the system that controls the airflow. There can be several things wrong with it so it's best to have a pro look at this to determine the cause.