BUICK DEFROSTER NOT WORKING

I Noticed That My Defrost Isn't Working But When I Switch It To Vents Or Floor, It Switches. I Removed All The Driver Side Trim To...

The Fan Works And Sounds Like The Door Is Trying To Switch From Vent To Defrost, But No Air On Top Of Dashboard.

The Car Takes 15 Minutes To Get Warm It Dose Not Seem To Get That Hot The Defroster Blowing On The Windsheild Dosenot Defrost The...

My Defog In 1991 Park Avenue Quit Working. What Do You Think Is The Problem