2000 Ford Taurus windows fog up as soon as I turn on defrost?

Soon as I turn my defrost on all my windows instantly fog up to the point that I can't see. Heater is not blowing as strong as it use to and car idle seems to be losing pressure when I drive it. When sitting idled the oil light flickers lightly but I don't need oil and my heat works fine except the fog that had me sitting in the middle of highway 99 unsble to see. When I crack my windows it doesn't seem to fog up as bad but they defrost slowly. Could this have anything to do with a vacuum hose? There are no leaks in my car not does it smell like antifreeze. Thank you for any intelligent responses in advance. I'm not replying to negstive remarks cause I will not stoop that low to play no matter what you say about my car or I.

I have had cars that do that and I always blamed it on having excess moisture in the car.

Means its on recirculate

Defrost is an A/C function that sends dry air to the window. It takes a few minutes to dry/defrost windows.

LOCO

If you have AC, turn it on and set the heat to high. The AC pumps dry air and that makes your windows clear up faster. Some cars automatically turn on the AC when you select defrost (both of mine do).

Turn the climate control to fresh air. NOT recirculate. You can also run the AC with the heat if you put the air flow to the floor and windshield position. Many cars won't let the AC run with the heat if you have the air flow set to only the windshield. When the AC is run with the heater it dehumidifies the air inside the car and helps clear the windshield.