I was wondering if anyone has encountered a problem with the ac blowing just on the front window. For some reason it stopped blowing through the front vents completely. I would like to try and fix this if it is at all possible.

Thanks guys...

 

Somehow you have lost vacuum to the HVAC controls. This vacuum is supplied through the vacuum switch on the transfer case if you have 4wd. Run a search cause I know I have posted the vacuum routing and diagnostics before.

 

I had a very similar problem if not the same. I ended up changing a vacuum "pump" or whatever it's called that controls the airflow. My blazer had three of them and one was acting funny so I changed it with one from a junk yard and it started working fine. But to do that you have to take off the whole dashboard and that is not too difficult but will take 2-5 hours.

Hope this helps,
keep us posted on the process