[Rolychick]

Awesome post! Five years later and it’s still educating us. I know it has been awhile since your post, but if you happen to have the pics for this, can you repost them? I’m going to attempt this as soon as I get my actuator from rockauto. Thank you!!!

 

[Rodger R.]

Thanks for the great detailed explanation - I reckon that saved me about $400 in dealer labor. My Enclave was stuck at defrost mode only. I bought Athe Dorman 604-140 from Amazon for $41 but I expect the cheaper $27 version would work just as well. There is no explanation of the difference on Amazon. I replaced the blend actuator in about an hour with your instructions. The screws drive into plastic so cannot be undone with just fingers. I could have saved a lot of time if I had a miniature ratchet with Torx bit. Instead I made do with a Torx bit and a short 1/4" box wrench taped together. I opened up the old actuator and found it had a burnt resistor on the circuit board. I see why you said to remove the blower case cover under the dash - that is how you get your hand in to get to the screws.
Thanks again.

Exactly my problem. 2012 Enclave stuck in defrost mode. So it’s the blend actuator I need to replace. 1st I heard there’s more than 1 actuator is this forum. Funny that autozone and Napa never asked me which actuator I needed when I called to check if it’s in stock. Hopefully the actuator that I see on the passenger side, left of glovebox, is the blend actuator. Anyway to ensure I’m replacing the correct one? (Going soon to harbor freight to buy cheap right angle tool.). — Rodger

 

[Kdraggoo]

I don't have the $1k OBD scanner to test the circuits so I had Buick do it for me. Turns out, all 4 actuators did go bad simultaneously. Something about jumping the car spiked the actuators and they all went too far. (See the photo for details. The notches in the metal tube, identified with the red line, should not go past the indicators in the plastic housing, identified by the green lines.)

I replaced them all and everything started working again, though I still have wounds on my hands and wrists from the effort. (Process clarification: I replaced the battery at the same time so the system was without power for well over an hour during this endeavor.) I recommend taking photos of which wiring connector goes to which actuator if you're replacing more than one. On the passenger side, they are close enough together that it wouldn't be difficult to mix up the wires.

Also, I used the same model actuator from Amazon for all 4 positions.

 

[rbarrios]

glad the jump start didnt fry the vehicles computers.
Thats why I no longer jump others with my vehicles.