This 2004 Chevrolet Trailblazer came in with the air flow stuck coming out of the defroster. I have already done a post on how to replace the faulty mode actuator, but I did not have a good enough picture to identify all of the actuators on the driver’s side of the dash. To see that post please click here. The view below shows the three actuators and is taken from the perspective of the driver’s feet, looking above the accelerator pedal and towards the center of the dash.
If you click on the picture it will enlarge to show more detail. This layout generally applies to 2003, 2004, 2005 2006, 2007, 2008 and 2009 Chevrolet Trailblazer and GMC Envoy. It also applies to Buick Rainier, Isuzu Ascender, Oldsmobile Bravada, Saab 9-7X and Chevy SSR. This second group of vehicles, of course did not exist, during all years between 2003-2009.
Once the mode actuator is removed and the new one is ready to be installed, you will need to locate the indexing pin as shown in the picture below. That pin slides into the notch on the white gear on the actuator.
I slide the new actuator into place with the notch and pin aligned and then rotate the actuator slightly to align the mounting holes.
The actuator on the right is the new actuator and the indexing slot is clearly marked. Please click on the picture to enlarge for a better view. The picture also shows the over traveled (stuck) position of the old actuator.
If you would like to purchase the Mode Valve Actuator (part # 15-73596), you can do so by clicking here.
Since meineke refuses to fix i’m trying myself. I’ve got it removed but none of my local parts stores have it so gonna order it from your link. One question will it hurt to run the A/C while its disconnected, it blows out of vents now?
You may not care for this answer. It is a common problem but it is not their fault. It was an underlying problem that would have resulted whenever the battery was disconnected or just went dead. It is standard protocol to disconnect the battery to change the alternator. By the way the battery disconnect itself does not cause the actuator to fail and stick. Disconnecting the battery merely starts a factory designed recalibration process. The actuator already had an internal problem that was manifested by the recalibration process.
I carried my 05 trailblazer to meineke for a warranty covered alternator replacement. When we picked up vehicle a/c wouldn’t blow out of vents so turned around in their parking lot, they carried it back in and said it was actuator tried to reset but couldn’t.They say what they did had nothing to do with actuator but if i’m understanding these post correctly power disconnection causes this…any ideas on how to prove this to meineke?
Did you try a recalibration? Where did you buy your actuator?
My new part, out of the box was aligned similar to the one I took off and just like your old actuator is the side by side pic. I installed it just like it came out of the box and got the same result…only floor or defrost flow. So I took the new part back off, and turned the white are to match your alignment in the new part pic. This time when the car first starts I get a brief blast of air out of the dash vents, but then it immediately cycles to the defrost vents. Defrost or floor. ARGH! Suggestions? Also, any tricks to getting more room to work or a light in postion to help out. A man needs left arms for this job.