HVAC actuator info?

[Dshow]

Hi, I have a 2003 TB LT. I had just gotten done replacing the front sway bar links and was pulling it out of the driveway and a loud knocking started coming from the dash. Sounds like a HVAC actuator. With the AC on, if I switch to blow out the top, it is fine. If I change the mode to blow on my feet, it starts to knock. If I switch the HVAC to 'off', it also starts to knock...

Anyway, I'm looking for information on the front HVAC actuators... How many are there? What is the best way to get to them? Any diagrams?

Thanks in advance!

 

[freddyboy61]

Attached is a diagram of actuator locations and part numbers.

 

[TJBaker57]

Be careful about part numbers. Do your own homework and verify part numbers, especially with an early year model. They are not all the same through the years.

 

[TJBaker57]

Personally, I would replace both the Mode and Defrost actuators. They are right next to each other and the easiest 2 to get at. For easiest access after removing the lower drivers side dash covers by the pedals, renove the plastic air duct that runs across from center towards the drivers door side. It is secured by a plastic push pin type affair at the far end of the duct. It takes some longish flat blade scdewdriver(s) to pop it upwards. Should have reasonable access after that is out.

 

[Dshow]

Thanks everyone!
I went out to see if my code reader would register any codes... It did not. Anyway, the clicking (or banging because it was loud) sounded like it was coming from right above the radio in the center of the dash... I would manually change the modes and they all appeared to be functioning, except for the banging when I set to blow out the bottom alone. I would press 'Recirculation' during the banging and it would flash a few times and then stay off. So I was guessing it was the recirculation actuator....? Since it appeared to be working other than the banging, I recalibrated the actuators by pulling the HVAC B fuse. After recalibration, I started it up and everything appeared to be working and no banging... I will use it a few days to see if it is really 'fixed'.

Is the recirculation actuator a PITA to get to if it does it again?

 

[TJBaker57]

Is the recirculation actuator a PITA to get to if it does it again?

Thd recirculation actuator is far and away the worst. I think it requires removal of most of the dash and maybe more.

 

[Mektek]

In an 03 I would bet that all the actuators have cracks in the gears and are on the verge of failure.
Poor design that puts the final drive gear under constant tension. If you are very handy they can be repaired, but most people just replace them. I've seen some of the newer ones that are better designed than the old first generation units.
The recirc actuator replacement shortcut is to cut the metal dash support out, then no need to remove the dash.
I repaired the three driver's side actuators and corrected the design flaw. So they should last forever!
For some reason the passenger side has never had a problem.
Before you tackle replacement be sure to carefully listen to locate exactly where the clicking is coming from so you change the right one.

 

[TJBaker57]

recirc actuator replacement shortcut is to cut the metal dash support out, then no need to remove the dash.

I think that is for the passenger side temp blend actuator and not the recirc???

I haven't had to replace either of those in my 2002 (build 2001). I never use the recirc anyway.

 

[Mektek]

oops! Yeah, that's right. You can bet that I would be cutting and bending - anything to avoid removing the dashboard

 

[Dshow]

I read somewhere you can access one by removing the glove box and going in that way... Has anyone done that? Hopefully that is the recirc actuator?

I have a set of GM service manuals and to replace the recirc actuator, they wanted me to remove the HVAC Module Assembly first which required draining the AC system... (Which I will not do...) Looking for a better way.

I drove it a few miles today... The constant clicking is gone, however, when I switch modes, I may get 1 click and then it works as it should... Hmmm.

 

[Mooseman]

Try to find which one is failing/clicking by feeling each one and changing modes to feel it. It will likely completely fail so might as well replace it now.

We have a whole section in the FAQs for HVAC issues with a few threads about actuators.

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