Ohhh, I see what you mean, it controls the air mixing damper (or whatever it's called)

My bad

 

so could this by when "testing" the car for heat and cool. More so heat.....I could not get it to blow HOT NOT air?? as temps here are about 65-70? I turn temps all the way up to test the heat when I bought the car. have yet to get HOT NOT air........

Thanks...just want to make sure my heat is working for winter !!!!!!