I have a 96 blazer and my a/c is stuck on defrost wont blow out vents. Happened once before but worked again the next day. Now it has done it and wont go back.

 

Auto or manual climate control? For either, the modes require vacuum to the head unit to work.

 

Welcome to the forum!

I would advise using the search function to see if others have had the same problem as you. This one seems pretty similar and I searched for 'vacuum hvac' after some preliminary searches about A/C being stuck in a certain spot. Good luck and I hope you find what you're looking for!

 

its manual

 

I have the same problem with my 97. Except from what I am gathering, mine is just the switch.

I turn it, and it doesn't even click anymore.