2000 Suburban hot air only and no cool air

[jgl38017]

I have a 2000 Suburban which is only blowing hot air from the vents. If I turn the temp selector to cold it still blows hot air. Even when I press the button for AC it still only produces hot air. Any ideas would be most appreciated.

[j cAT]

Originally Posted by jgl38017

I have a 2000 Suburban which is only blowing hot air from the vents. If I turn the temp selector to cold it still blows hot air. Even when I press the button for AC it still only produces hot air. Any ideas would be most appreciated.

in the duct of the air box directly above the tranny hump is the air temp door blender . this is a stepping motor device that moves the door that varies the air flow across the heater core.

many times this will stick due to debris or the device is failing.

tap on the vent ducting in this area and see if it unsticks. if not remove it and clean the vent ducting. if clean and no operation , then you will need to replace it.

there is no control for heatercore coolant . the coolant constantly flows thru the core inside the air box. changing the flow of air varies temp.

[jgl38017]

That seems to have fixed it. I removed the shroud and tapped the door blender a few times and it appears to be working now. Not sure how long it will last but at least I have an idea what it is if it comes back.
Thanks again

[j cAT]

Originally Posted by jgl38017

That seems to have fixed it. I removed the shroud and tapped the door blender a few times and it appears to be working now. Not sure how long it will last but at least I have an idea what it is if it comes back.
Thanks again

since thats it then , avoid placing the temp to full hot. do 3/4 hot only on temp control.

3X I have had to do this over a few years now.