1998 Blazer w/ auto climate control.

Heat will not cut off, blows hot air in all ac, panel and temperature settings.

I've checked vacuum operated doors I found (recirculate door, directional door) and they are operating properly.

I did not find any type of heater core bypass valves in the heater core lines, so there must be a door within the heater/ac box assembly.

Can anyone help me find it? I'm guessing it is vacuum actuated also.

Is there a quick and easy...down and dirty fix?

If it's located up in the center of the dash it looks like a bear of a job....

Thanks from a newb,
Guy

 

It is electronic. It is located on the top of the HVAC box on the passenger side and is barely accessible with the glove box dropped down and out of the way. It is called the temperature door actuator.

 

swartlkk,

Thanks I appreciate the help. Darn that was quick!!!!

Is it possible to test? Is it subject to cold solder joints (repairable circuit board?).

I see you answer an awful lot of posts on this forum....That's great when people pass their knowledge along.

Thanks again,
Guy

 

There is a gear in the blend door actuator that breaks (plastic gear). The actuator is expensive ($150 or so) and the one for the auto climate control is different from the manual heat control. And it's really hard to get to (through the glovebox opening).

There is a write up at

http://www.automotiveforums.com/vbul...d.php?t=574779

that might help. Good Luck.