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.). — RodgerThanks 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.
I installed the actuator on the driver side and removed the HVAC fuse. After 30 minutes, I put the fuse back in. Turned on the car. Set the a/c to Auto (it was off). Waited a minute. Turned the car off. Waited 15 seconds. Turned the car on. Held my tongue to the left, wiggled my right ear and tested the a/c controls. No improvement.
I’ll probably take another actuator out tomorrow and disassemble it. Sounds like a good way to spend my evenings.
BTW, anybody know how to test the sensor circuit in the actuator?
I have a problem with getting cold air on both sides of front of cab with cold air in rear of my 2012 enclave after changing battery. I seem to have lost program after battery was out of car for a few days. when i switch mode from defrost to dash to floor the blower blows out of correct vents but only hot air. I think it has something to do with the temperture actuator. any one knows witch one controls and location of temp. actuatorGreat post and idea to drill. Removed the actuator in 5 minutes.
When I replaced the actuator and connected everything, I tested different heat settings to watch the circular piece turn the door. Everything works fine again, except the blend door actuator does not immediately turn with different settings. The actuator turns a little, stops, turns more. It does not seem to continuously (smoothly) move through the range when adjusted from full hot to fold cold. For example when I change the vent settings the actuator in front of it moves continuously to the new setting. I'm thinking the door may have resistance and that's why the other motor may have burned up.
One more supporting piece of information. When using the main temperature control, not just changing passenger setting, the driver vents changed immediately from hot to cold while the passenger vents lagged behind a bit (that intermittent adjustment I spoke of above. Is this normal characteristics of movement anyone else has witnessed?