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.
This is the link address for the article that you need. There is a link within the article to additional information. You will need to copy and paste the address.
http://www.sparkys-answers.com/2012/01/2003-chevrolet-trailblazer-changing.html
My ’03 trailblazer EXT rear air only blows hot air. Where is the actuator located for the rear air? Is this the first thing I should check?
How did you have the refrigerant charge verified? The only true and accurate way is to recover and measure the refrigerant. Everything else is a guess, although it can be a very educated guess and close. If the fan clutch was the issue your complaint would have been more along the lines of cools good at highway speed but not in traffic or at idle.
Thanks for the response about the actuator part numbers being the same for the manual or auto control. I’ve verified that the refrigerant is fully charged. I had the fan clutch replaced last year, could this be related?
Check the refrigerant system. Your description of symptoms is more in line with low refrigerant charge than actuator problems. The driver’s temp door actuator however is the same part number regardless of auto or manual controls.