Why are my windows fogging on my 2003 jaguar x type?

The outside air vent is stuck in the close position, so no fresh air is entering, you're just recirculating the inside air. The motor, located behind the glove box, is working but has become striped where it connects to the vent flap. Jaguar has a TSB explaining how to fix with "krazy glue." Or you can manually open the vent by accessing it from the engine bay behind the cabin filter. If you go this route, just remember not to use the recirculating switch.