Hello experts...

In my wife's 1994 Maxima, cold air (and I mean cold) blows out of the dash vents (even with the dials closed) while the heater is on. Hot air comes through the dash vents on top as well as down behind the console (radio), but the air vents on the front have cold air coming out (even with the little up-down switch next to the heater controls in the down position - what is the purpose of that switch anyway?). What could be causing the cold air to blow through the front when hot air is coming out on top? Is the heater control valve bad? Is it the little switch I mentioned that has two positions (up/down) with the blue-wavy lines at the top position? I assume the purpose of that switch is to "block" airflow through the front vents but it doesn't seem to work - maybe that's the problem?

Mark

 

the wavy line lever should be down.
it is a fresh air control

 

We've tried the lever up and down, it didn't make a difference - cold air still blows through.

 

the cable or lever is probably broke then. Look under the dash adn there will be a lever with the cable going to it (nothing else around it...not motor or anything). see if you can move it by hand.