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.
hi, i have a 04 trailblazer with dual manual climate control, the ac works throughout the vehicle with exception of the drivers side. it blows out warm air but not cold. do you know what would cause this to happen and how to fix it?
Thanks
With the help of this website I was able to fix my 04 trailblazer mode actuator problem. My local dealer quoted a price of fifty something, but when I arrived they changed it to eighty something. They also tried to sell me an actuator with a gear that was way out of alignment. I don’t think I would have been able to install theirs. I paid 25.00 at a junk yard (gear aligned just like your pic) and with the help of a little double stick tape to hold the screws it works like a charm. Thanks a million.
Yes it is an actuator issue. Try doing a system recalibration. You can find the procedure on the left side bar menu.
I’m having similar problems in my 04 GMC Envoy. The only difference is, my heat only blows out of the dash vents. I’m unable to use defrost or floor vents. Also, my A/C compressor is getting cold, but no cold air will come out of the vents. Do you think this is an actuator issue??? Please help!!
It should be okay for a few days.