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.
Most of the time, my 2003 Trailblazer EXT blows cool, not cold, air out of the passenger vents, and hot air out of the driver’s vents. The air gets hotter if I adjust the temperature setting. I’m thinking that I need to replace the Driver’s Temperature Door Actuator, which I believe would be part #15-73598. I have the dual zone automatic hvac controller (the one with a digital readout) is the actuator part number the same for the automatic controller as for the manual controller?
Sparky, thanks for the blog! My actuator went out last summer, and after reading this blog, I tried a couple of times to replace the part in the fall and winter, but was unsuccessful: Too tall, and man hands to get under the dash! But, I gave it one last shot today prior to conceding defeat and taking it to the dealer, and lo and behold, SUCCESS! Course my neighbors will refer to me as “The Cursing Neighbor”, but that’s OK. Thanks again!
Thanks, Sparky! It took a while, and laying on my back scrunched up under the stearing column with only my left hand available for work was not pleasant, but it’s in and working.
Glad I had those small Craftsman 1/4″ ratchets; left, right and straight. Made removing the fasteners possible.
Which actuator are you trying to change? Does your 2005 Trailblazer have adjustable pedals?
I was able to locate the actuator, but find it almost impossible to remove. I cannot get in close enough to even see what type of tool to use to get it out. Any suggestions to get in closer or what tools I should be using to get it out? 2005 trailblazer