I have a 2000 Chrysler Garnd Voyager and I have been having problems with windows fogging. We have checked for a leak in the heater box and also the drain coming from the box. No problems with either. I believe the vent system is stuck in the recirculate mode and this is not allowing the moist air inside the van to be vented. Does this assessment make sense? How do you get to the door that makes the system go into the recirculate mode? Would a vacuum leak in the vent system be a likely problem? Thanks.

 

clean your window, thats most of the prob a film will build up and u can see the air change. Next do u smell something sweet ??

 

And if you do, that sweet smell is coolant leaking from your heater core and causing serious fogging on the windshield. If the system IS stuck on recirc, you will probably need to replace the heater control unit.

 

humm yes and no i asked if u smell some thing sweet it trace down electeral or doors or a coolant leak dont scare the guy. Replacing the HVAC unit i doubt it. I have never had to dont one for that issue b4 and i have been a chrysler trained tech for 12 years

 

Thanks to all who replied. I had already thought of a heater core leak and the sweet smell of antifreeze. That wasn't the problem. The problem was a stuck flapper valve that was stuck in the recirculate mode. It was not bringing in enough fresh air and therefore, just the moisture in a person's breath was enough to condense on the windows. I played around with the recirculate button and it finally changed the flapper from recirculate to normal mode. I hope it doesn't get stuck again!