SOLVED! Air Door Main Mode Actuator

[kdannyk]

I have a 2005 LT trailblazer. Last fall my main door actuator went out so it was always stuck on defrost. I just replaced it but the new one doesn't seems working correctly. Wondering if there is certain way the gears have to aligned when the actuator get's installed.

What happens is when I have truck in acc mode I get air coming through on the front vent. When I start the truck they will still blow air through front vent for about a min or so then it will stop and start blowing through the windshield vents ( deforst vents) even though the controls were never push to change them.

I have clue whats going on and need HELP!!!

 

[Mooseman]

Did you reset the system by pulling the HVAC-B fuse for about 30 seconds, replacing it and turning the key to RUN for a couple of minutes?

 

[Matt]

Do you have auto climate control? The auto system tends to default to defrost, especially when it's cold out.

 

[kdannyk]

I just did it again. Seems to be working a little bit better. I will have to go for a test drive to see if it stays where it's suppose to.

I do have auto climate control

 

[TJBaker57]

When I changed my mode door actuator I had a similar result, air still came out of the defrost vents. I found the defrost actuator had also failed and needed replacement. Luckily the mode and defrost actuators are the 2 easiest ones to change!

 

[kdannyk]

I HVAC-B fuse and that seemed to fix the issue. Air has been blowing out of the proper vents. Thank you for the help.