Chevrolet Repair: 2001 Chevy Venture HVAC, chevy venture, hvac system

Question
Mr. Bisig:
Thank you for your volunteering your time to this site. We have a 2001 Chevy Venture WB, 3.4L with 87,520 miles on it. When the temperatures get colder, 40F and below, the windows fog up pretty bad. We must keep the defroster on full blast at the highest temperature. The side windows get the worst. The windows will fog up even only with one or 2 people in there. Furthermore, there is absolutely no air, or none that I can tell, that blows out of the side vents on the dash corners. The service department says that is normal and that's how its designed and if I get alot of people in there, the windows will fog up...I can't see GM designing a vehicle with a HVAC system that can't support the passengers its designed to carry. The heater head had been replaced early last year under extended warranty, and it seem like it got worse from there. I'm starting to get frustrated with this thing. I think the side vents have something to do with it. What are your thoughts? Thank you in advance.  

Answer
Hi Tony, The first thing that comes to mind is the max/Recirculation door in the heater. If this door is stuck in the open position that will cause this to happen. The door should only open in the AC max position. I would have that checked out. The only other thing is the heater core, if it is leaking it will make this happen too. This doesn't sound like you though.

Have a Great Day         Mark