The previous posters were referring to the upper middle dash vents: there is a thumbwheel there that is scrollable
from red to blue; it's to allow cooler air on face, with heat on through floorboard vents...I don't think that's your problem
as I can bake our feet, and still get outside cooler air through the upper center dash vents, when I choose to.
I tend to agree with Weasel, as he has forgotten more about Xs than I will ever know.
Fwiw, our '01 pumps "heat"/warmer air, pretty quickly, as do the heated
seats...
GL, mD