I'm looking to replace the drivers side blend actuator, I have control over heat and cool, but here is no switching from the defrost to floor or vents, seems like its 95% or 100 % goingnto the defrost. Ive seen a good post here on all 4 actuators and part numbers, so I figure a $25 part is worth the shot with 8mm bolt to remove. But ixe seen videos where once you get the actuator out the (not sure if it's called the cam) but that circular plate behind the actuator that has the slots will fall out and it's a real pain in the *** to get set back in.

does anyone have any good tips to keep that plate in place? With the location i can barely see it wihile working on it, i think its going to be more of close the eyes andput the bolt back in by feel.

 

Dont forget to complete the blend door calibration once you have it installed.

This can be done with a Tech 2 tool or some have done it with removing the positive for about 15 minutes,
Re attach positive cable,
Now turn ignition on for about 5 min . Dont touch the AC controls
Turn ignition key off for 15 sec
Start engine. They should reset and be ready, cycle setting and verify proper operation, your done.

 

If a PO replaced the HVAC Control unit in dash with a Dorman unit you can just try the reset procedure H2-SUT mentioned above, but not with the Tech2 as Dorman warns against that in their product instructions. Works for some, not for others but worth the shot before the aggrevating actuator issue. When the shop replaced my actuator I tested the "old" one at home and found it to be fully functional as it had actually been the HVAC unit not sending signals to the blend and fresh air actuators.

Also - sometimes its just a matter of the actuator getting driven past its "stop" point, and then even with proper signal going to it, it wont move. So take the actuator out, and bench check it with a 9V battery. This procedure can move it out of the stop position and test it through both rages and set it back to the center. There is a YouTube video showing how to do this procedure. Once out of the stop and back on center, you can make it go from mark to mark touching only pin 6 or 7 individually. Install with slot aligned on center mark. Then run the HVAC reset procedure H2-SUT described.

https://youtu.be/vWBGKfl7k24?si=1i7KMjfGcRc8mYB6

https://youtu.be/gFsHHcpAzPY?si=ZHZqHVQBd-h9v7DT

 

I've had a Dorman HVAC module for about 9 months. Twice it's acted up, and been solved by disconnecting the battery and reconnecting after 15 minutes. The doorman unit will go through it's self initialization procedure like when it was new. Takes it 20 or 30 seconds. It's pretty much all we have to work with at this point, and they are known to have issues.

 

This is next on my project list. I got the Dorman. I am also putting in a Kenwood head unit and backup camera, so figured I might as well tackle all dash issues at the same time. On the other hand in terms of troubleshooting I'd like to sequence one and then the other. Do I need to pull off the center dash console to get to the passenger side actuator? Anyone been able to clean the ducts during this fix also? Filter? Thanks.

 

I haven't done it yet but please update your journey this is exaclty what i need to due also except I need to get at the deivers side actuator and replace the old bose stereo and run a backup camera before I run over something in reverse.
there is a really good post I saw on this forum for all three actuators and part numbers and stuff.

 

https://www.hummerforums.com/forum/h...answers-27779/


Jimbrew posted rgat ine if it helps youu

 

Maybe I'm wrong but doesn't the mode actuator door control the position of the door to direct the airflow to where you want it or maybe its called blend door actuator in these trucks. Normally the blend door controls the air temp and the mode door controls where the air goes, just trying to understand what actuator your looking to replace.
Defrost is the failed position of the mode actuator door,
I've been able to save a few with the calibration steps,

Neal

 

I know it comes up as "actuator" when searching for the part and mine is stuck in defrost, I've tried the reset unplug over night plug battery in and key in on positon let sit for 5 or 10 minutes .....etc and no luck. Tried unplugging actuator connection no luck and tapping with a small hammer no luck. The part is only $25; but from the things I've read the the real problem is the plate on top of the actuator, tends to fall out and is a nightmare to get back in. I'm gonna put a new stereo in anyway so I'm thinking it might be easier to get to that part with the stereo out then get under the drivers side spot to remove .

 

It's 13 degrees and the actuator I ordered got lost in the mail! But I think I'll start tomorrow with the stereo. So even though this is an actuator thread I'll post here as a response because I'll be pulling apart the dash for both and probably just go pay 2x for the actuator at a local parts store. I bought a Kenwood DMX7709S and had Crutchfield put together the plug and play pigtail for an extra $30. I bought a BOYO Heavy Duty Camera with Night Vision. The Kenwood is sophisticated enough for me to shape the sound inside the SUT with the existing Bose speakers and 200 w amp. But I can add on and vary the speakers if I decide to. I already have a backup camera, a DoHonest heavy duty magnetic camera that connects via wifi to a monitor I plug into the lighter. I highly recommend the DoHonest for anyone who wants a quick solution for a backup camera. I also recommend getting the one with the screen because otherwise you have to use your phone or a tablet to see the feed. These run about $90, plug and play. The DoHonest also has a solar panel and will charge throughout the day. Because I have a SUT that I've taken the rear tire mount off of, my license plate is offset and a regular license plate camera won't work. The BOYO is similar in appearance to the DoHonest and has an angle mount bracket. I don't want to drill to mount it and will add magnets to it. I expect I will use it side by side the DoHonest because I like the dedicated rear view. It is convenient to put the backup camera cable in while the dash is open though, so that's why I'm putting it in.

As for my actuator, passenger side is HOT and it is barely blowing through the rest of the vents. I bought the SUT when it was still warm this year and passenger side was HOT with cool air coming out of all the other vents with the AC turned on. My Topdon Topscan (which I also recommend) is bidirectional and it has run through the AC settings several times but is not fixing the actuator. I am capable of building circuit boards. If I can just fix the actuator, I'l try. PS yes it was super cold today but I just happened to find an OEM chrome grille on eBay in easy driving distance for $130, went and got it and put it on this morning. The SUT is my winter project car.