Blend door actuator

[jaywestfall]

Thanks y'all. This is really helpful. While the old motor is out, my 1998 is getting a rip and replace on the HVAC, and this commentary answered lots of questions!

 

[RichardSwinger]

One of these gears is not like the others [emoji28]. I wish I could just order that single part, all of the gears slide out very easily. The recirc blend door is absolutely different from the other blend doors and you have to look closely at the electrical connection (recirc actuator only has three pins on the right side, others have four pins on the left side). I got to do the olde double trip to the parts store today with the wrong part, even took both apart to see if I could cannibalize the main gear but it has an internal stopper where as the recirc actuator has an outer stopper.

The writeup from someotherguy on chevytalk was extremely helpful, not sure why I can't get that forum on Tapatalk. My goodness, if I read it correctly, that thread was from 2007. Someotherguy and his 14 year old posts transcending time and space to help me figure out how to fix this old truck, I love it.

I tried to find one with that metal center piece but no luck so I'm going to go with a doorman actuator when it shows up at the parts store tomorrow. Getting it out was a real motherbear with that top screw and I am not looking forward to putting it back in there.

What a strange design! I messed around with the post that moves the recirc door and it is surprisingly heavy to turn counterclockwise (which isolates outside air and puts it in recirc mode if I understand correctly) and when I let it go it swings clockwise as if it is weighted and that is the preferred position. No wonder these gears strip out! I guess I figured it would swing freely between the two positions and not have a "preferred" fail safe position.

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[1madmouse]

I did search for Blend door actuators and found a couple of AC-Delco guys that tell you how to time these so it has the right travel. The blend door right above the accelerator is different than the others. The large gear cracking seems to be the main problem, some people even JB Weld the gear back on the shaft and go that way. Prices for new are all over the place.