With the recent warm weather I have noticed that while driving the A/C will suddenly quit blowing out of the dash and start blowing from the defroster. THis only happens for a about a minute and then switches back. I can expect this once every 4-5 minutes. Can I just pop up a access panel on the dash or do I have to tear everything apart to find the actuator and vaccum lines?

Is this a common problem and is the an easy fix?

 

It might be. I had the same problem. It only happened when I accelerated. The dealer found a crack in the vacuum tank. It is located behind the battery(on my truck). Although, you may have a vacuum leak anywhere I think this may be a good place to start.