So I've had my '00 XJ for a couple of months. Last night was cold and wet. When I left early this morning for work I noticed the windows were foggy. I cranked up the defrost which seemed to work ok but it barely cleared the lower half of the front window, let alone the sides which remained foggy. What am I missing here?

 

One of the side windows:

 

And the other:

 

Clean you glass. Dirty glass is MUCH more likely to fog and less willing to clear up. As long as your AC works, your defroster will dehumidify air; if your AC is shot or you have none, you'll really need clean glass and will have to dial the temp of the air just right to keep condensation from accumulating on the glass.

The arm that opens and closes the defroster also commonly breaks on 97+. If you hear a clear *THWAP!* sound when you turn your blower on, your defroster door is likely being blown shut by the airflow in the HVAC box.

 

Well, I did thoroughly clean the windows so I know it's not that, however my A/C did go out so maybe that's the issue if its relying on that for balancing out humidity like you said.

 

Rain-x anti fog every time you clean the windows.

 

Bingo. No AC = no dehumidification.

 

Man, how did we de-fogg a window in the fall when we didn't have A/C back in the '70's????

 

7-11 napkins

 

Probably just turned the heat on until the windows got warm enough to evaporate the condensation? No idea I wasn't around in the 70's haha

 

Or this

 

And in the 60's

 

true, I kinda remember doing that a time or two!

 

If your heater isn't blow as hot as it should foggy windows can be a sign of a bad heater core in the early stages.

 

If heater core is leaking it does fog up windows but will usually leave a greasy film on windows also.