heater won't change

[snakes44]

I have a 1997 cavalier and the heater works great as far as warmth and fan but when you try to switch the blower from the vent or defrost position to the foot position it will not change does anyone know what may be wrong or causing this issue any help appreciated Thanks

[shorod]

Since your question is pretty specific to a particular make and model, I've moved your thread to the vehicle-specific forum.

-Rod

[RidingOnRailz]

Originally Posted by snakes44

I have a 1997 cavalier and the heater works great as far as warmth and fan but when you try to switch the blower from the vent or defrost position to the foot position it will not change does anyone know what may be wrong or causing this issue any help appreciated Thanks

Is your climate control a simple "three knobber" - Fan Speed/Mode/Temperature? No pushbuttons or pax-side controls? Does it affect temperature - when you turn it to the blue side(cold) does cold air come out?

This failed on my 1981 Buick Century back when I owned it and in my case what needed replacement was some kind of vacuum interface(there is a correct name for it I don't recall).

It looks like a piece of plastic/rubber with holes in certain locations. Installed, it controls the flow of vacuum to certain doors inside your dashboard that direct heated/cooled/compressed air to either the floor, out the dash, or up to the windshield. Conventional climate controls have worked off the engine vacuum for decades, and it's likely that '97 Cav of yours does too.

This function may also be electrically actuated, when you switch the mode from floor to dash to windshield with the engine off and the key in accessory mode you may be able to hear the different doors opening/closing. In that case that portion of the switch may be broken or current is not reaching it or the doors controlling the direction of airflow.

Hope this narrows it down.