I live in Minnesota and have been having an issue this winter when the weather gets really cold (sub zero). The windows fog up, all around. The defroster can barely keep the windshield and only the front portion of the front side windows cleared. I don't smell antifreeze in the car, nor do I see any wet spots inside or outside of the car, nor have I seen a loss of antifreeze.
The air coming out of the defrosters are hot, and when the outside temperatures are very cold the moisture on the inside of the windows will frost over. It would seem like I am putting moisture in the cabin; anyone have any thoughts where it is coming from?

 

Turbine, you may want to have your A/C system looked at. I know you are thinking I am nuts, but the A/C system actually gets a lot of use during the winter. What happens is as the defroster pulls in the cabin air, it runs it over the A/C cooling coil to cool the air down and remove the moisture from it (colder air can not hold as much moisture as warmer air). The air is then run over the heater core to warm the dry air up so it can be blown over the windshield. So, if you are not initially cooling the air, you are effectively blowing the warm moist air over the windshield and it is most likely at the point that it can't hold any more water (ie, the frost/fog on the windshield) and therefore it leaves what it can't hold behind.

 

Turn your recirculation off. Then pull your cabin filter out. Right behind the filter is a blend door. Check to make sure the door is open. If it is stuck shut you will get fog inside.

 

Thank you gents. I will check these things out when I get back home early next week. Easiest and first to do is check the blend door. I assume access to filter is below dash on passenger side? Recirc is auto-off when defrost is selected; I have tried to cycle the recirc during non-defrost operation, but do not know if blend door is actually opening. If that is operating correctly I will check out the A/C.

 

This might help you. https://www.jaguarforums.com/forum/x...indows-110519/ https://www.jaguarforums.com/forum/x...ging-up-93113/

 

Excellent Jac, I will check that out when I get home. I will post results... Thanks again..

Turbine Guy
2002 Xtype 2.5L Manual