He put the wrong actuator in there. I was searching several websites and message boards about this problem, finnaly took a look at the reciept and looked up the part number, its for the one with manual climate control not automatic. I found a thread where someone else got the wrong part as well, gonna get a small ratchet set and see if I can get it out with only opening the glove box.

 

Got the actuator out, you have to disconnect the hose and pump that switches the air to floor, top and defrost vents, and swing it out of the way.
Luckily the mechanic skipped the third screw in the back so I was able to get it out fairly easily with a small ratchet set. I tried testing it before installing, that was a mistake, when the system re-sets it feels for resistance from the door on both sides, without installing it it will just turn one way and stop. I had to pop open the actuator and reset the gears to install it.
Here's a thread that shows where its located and some other actuator tips:
http://www.automotiveforums.com/vbul...d.php?t=574779

 

im having the same problem with my blazer i see the temp door on the figure you provided. would oyu have an idea of where it is located and do you know if i'll have to remove the dash to do perform this work. its my daily driver so i can't afford for the truck to be down for very long. thank oyu for any help or hints.

 

Check the link I posted, two of the screws were somewhat easy to reach and remove, the thrid one in the back, not so easy.

 

you don't have to take out the third screw behind to get the blend door actuator out... The one behind and to the left of the glove box. God I wish there were only one name that people used for these doors. motors. actuators. I understood that the one behind the glove box to the left and above and behind a vaccum controlled diaphragm that you can swing out of the way was called the blend door actuator motor and is electronic. I am hoping that that is the only electronic actuator in the system. Can anyone clarify that for me please. Where is the temp door actuator that people are referring to??, the temp door actuator, and is the temp door actuator just a vaccum diaphragm???

 

Reviving an old thread:
Actuator gear is fine. Blend door travels back and forth when key is turned on. I can feel the heat, then the cold as it's working. Then...cold. That's it. Temp **** on dash doesn't move the blend door. I have my finger on the shaft as I turn the ****. This is the automatic system, obviously. Could the problem be the "head unit" in the dash? Air direction, vents, everything else works except the main blend door is unresponsive, even in automatic mode. I guess I will have to spend $250 and get a new one from the dealer. The replacement one I got at the junk yard must also be faulty then, because it's doing the same thing. What are the odds? I wish I could find a schematic of the circuit board behind the *****. I'd fix it. Anyone else have to replace the "Head unit"?