I have a blazer -99 with climate control air condition.

The problem is that it doese't matter where I have the temp knob. It will always come hot air from the vents.

Can someone tell me if the heat blending/mixing door is controlled by a electrical motor or vacuum cotrolled?
And where is it located in the truck?

And if someone have some wiring diagrams or vacuum diagrams to my truck.

Best Regards, need to cool down [:@]
/Sverker

i would check for a vacuum line under the hood going trough the firewall for break or crack .

Hi,
After 4 hours of work I have found out all kind of things aout the heating system in a Blazer -99 with Computer climate control.

All the dampers for air on floor, window, etc are controlled by vacuuum.
But the damper that controlles the heat is a servo motor.

Now I have a electrical diagram for a Blazer -99, someone that know where to find one?

/Sverker

I know that this is an old post but I have the same problem. Did you get the issue resolved? What did you do to fix it?

Please start a new topic with your specific problem and any trouble shooting steps you have attempted.

I have opened a new post, it's title is "Only blows hot air ".