Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner


  1. Driver Side HVAC Actuator

    Hi, first I'm new in there and I'm grateful for the forum community. i have trailblazer 08 that started blowing hot air from passenger side and cold air from passenger side when turning A/C on.:crazy: i tried all the calibration, battery off but it seems that i need to change the actuator...
  2. HVAC Issues

    So I'm at a loss. My HVAC has the following list of issues: The air is blowing out of all vents. It is set on floor, and if you hit the mode button it will start clicking behind the dash. However, it still blows full out of the vent and defrost. In other words, when I don't want it coming...
  3. About to attempt a Door Mode Actuator replacement

    The 02-09 "How-To" and DIY Section
    Hi all, like the title says I am planning to replace the Door Mode Actuator on our new to us 2003 Envoy XL SLT with the dual climate controls. I actually found this site when our mechanic said it was a $500+ job to remove the entire dash and replace the part..yikes. I sourced most of my info...
  4. Very quick and simple possible solution for HVAC control and Calibration

    The 02-09 "How-To" and DIY Section
    I'm hoping this will help a few folks with HVAC/calibration issues. I recently had the control module to my heater motor fry. Upon fixing it I quickly realized I had other issues. The HVAC unit would only blow hot air on my feet and it would not switch to any other position. I went through many...
  5. Replacing Blower Mode Door Actuator - HELP! Major Issues Now!

    OEM Issues
    So I followed the instructions found here: Got the old one out, no problem. Set the new one to match the old one (line up on third notch). I cannot get the actuator to seat properly. I realized that the teeth on the actuator are not aligning...
  6. [SOLVED] (NOT SOLVED!!) Actuator Gone Wild

    The 02-09 "How-To" and DIY Section
    Hello all, I've read through this site for years but never posted until now so here it goes. I'm in the process of replacing the mode door actuator on a 2002 Trailblazer. I got the old one off put the new one on, but this is where my problem is. While calibrating the actuator, I noticed that it...
  7. [SOLVED] 2004 GMC Envoy Actuator

    The "How-To" and DIY Section
    :)Hello - would like to know if the blend door actuator and the mode door actuator on the 2004 GMC Envoy - SLT-V6, 4.2- 2wd are the same part or different parts. Also where is the location? Please advise if you have knowledge about it.
  8. 4x4 selector switch have no lights, no front tire engagement

    4x4 Drivetrain
    Great site! Anyway I have read through all the forums and can't quite get the answer I'm looking for. I have a 2006 trailblazer with the 4x4 service light on and no lights on the selector switch (they light up on start up so they work) and of course no 4 wheel drive. I turn the selector switch...
  9. Hvac drivers blend door inop?

    OEM Issues
    I've read all the threads on how to replace this thing, but I can't see what's wrong with the one I've got? I can only get heat in all modes out of the drivers side vents. I pulled the blend door actuator off and did not see any stripped gears whenever I took it apart. I reassembled the cover...
  10. Lining up a AC mode actuator

    I decided to start a new thread on this subject as all the other treads were very old and did not answer the question on how to actually line up the ac mode actuator. I have removed the old one and I am ready to install. People have posted that you should make sure it is in the same position as...
  11. A/C Issue

    I have no air coming out of dash vents. A/C compressor works and all other vents have air coming out. I think it is the acuator problem, but I dont remember part number or link on how to replace. Does anyone have this info, and do you think this is the problem. Thank you
  12. HVAC Mode Actuator: Which one do I replace?

    I have the HVAC Mode Actuator click or pop, when it occurs, usually three sharp cracks. Looking around the forum, I found that there are 3 actuators in the system. Is there a way to verify or tell which one needs to be replaced? In my case it might be related to the a/c because we had a warm...
  13. Ongoing intermittent 4wd issues

    4x4 Drivetrain
    So, here's the rundown of what's been going on , what i've done and where i'm at. The Service 4WD light has been on steady while in 2WD in all kinds of weather, rain, snow or shine, for about a year now, but occasionally goes away and 4WD does work, but then light comes back on and away goes...
  14. encoder motor replacement

    4x4 Drivetrain
    I have ordered a replacement encoder motor and will be changing it myself any tips on this? i looked in the forum for how to's or pictures but couldnt find any. any advice would be greatly appreciated!!!
  15. getting to the defrost actuator

    Hi there, After reading a few threads I'm pretty sure the annoying clicking coming from my dash when I turn the Envoy on is the Defrost "Door mode actuator". (clicking when on anything with defrost, lasts about 10-15 seconds, getting worse by the day) does anyone have a good detailed...
  16. New Trailblazer - CPAS?

    OEM Issues
    Hello everyone! This is my first post here. I just got a 2004 Trailblazer LS with 126K miles a couple of days ago. It ran fine but I was bored so I started doing some of the stuff listed on this site. So far I've cleaned the throttle body (unhooked the battery for about 2 hours), put a new air...