vent

I am trying to figure out why I can get proper airflow through the defroster vents and the feet vents, but nothing from the front vents. Note: On the dial, front vents (the ones not putting out air) is to the left, feet in the top middle, and defroster to the right). After a bit of reading...

so, the floor heat/ac stopped working on my 08 cobalt ls, the front and defrost vents seem to still work like they are supposed to though. when I turn the dial to go to the floor setting, I can hear stuff In the dash switching, but still just barely a trickle of air comes out of the floor vents...

I kind of know what my problem is but do not know how to fix it--the cannister valve\soleniod back by the gas tank that is inside the cannister does not close when the car is turned on or started-i have replaced this valve and also have taken the valve out and applied 12v to it and it closes--i...