2002 Chevy Venture. Engine size = 3.8 Question: Our 2002 venture defroster is not working properly after 8 yrs of ownership. It seems to work well if we are sitting still. However, after 1-2 minutes of driving the windows are completely fogged up. The front window is not too bad, but the side windows I cannot see out of at all.
If I stop the van and sit in it with it running, it will completely clear after 2-3 minutes. You can visibly see if clear! Then if I start again, it will fog up again and the defroster cant keep up with it. With the cold days we have been having lately, the inside actually frosts up(ices over) and we have to scrape it off.
It is very dangerous b/c I cant see to turn! Sometimes I cant get my windows down because they are frozen, so I cant even crack my window like my mechanic recommended I do. I just don't see anyone else riding through town with their windows all fogged up on the inside. My mechanic has looked at it twice. The heater core is fine. The vent ports are working properly. The amount of heat coming out seems fine. My husband religiously completes maintenance on it and last changed the cabin filters in Feb 2010. The mechanic said it has just been a cold winter, but we have had it for 8 years and never had this problem and it is getting worse. Plus my husband and i agree it is very dangerous. I cant see to back out of parking spaces. Someone has to get out and direct me, which I cant do when I am alone. Do you have any advice?
Answer: Usually a problem like that is due to something not working properly in the HVAC system, or having a leaky heater core. If, as you say, the heater core is fine, and the vents blow enough air and change modes properly, there is really nothing that can be done. Extreme cold temperatures will cause this to happen, and there's just no getting around it. You can try to warm your vehicle up until it is fully defrosted before traveling anywhere. Also, cleaning the inside of the windshield and windows helps greatly! If you're a smoker, or otherwise have dirty windows, it allows them to fog up rather quickly. You might want to check that there are no air leaks around any of the glass, or bad seals/weatherstrips. That would let in the cold air that is fogging up your glass.