HVAC actuator noise

[xavierny25]

Hey guys I'm just try to get an idea as to which actuator is making all this racket. It doesn't happen all the time but it's getting more frequent and only happens when the system is set to auto at what ever temp I set it to. Once I lower the fan speed to get out of auto mode it goes away.

 

[Mooseman]

Have you tried feeling for it as it's making the noise? What about manually adjusting stuff in manual mode and listening for it?

 

[xavierny25]

It seems to vibrate the whole lower panel in that area when it does happen. I haven't been able to reproduce it in manual mode. It seems to act up when the interior temp reaches the set temp and the fan speed (on auto) start to lower.

Would It be a good idea to just replace all the actuators since this one is acting up? I really would just like to tear into the dash once and be done with it.

 

[Mooseman]

Since it seems to be related to the fan speed, maybe it's the fan motor or the module? Since it's a PWM control, maybe the motor is producing a noise to it. Try disconnecting the motor when it starts doing the noise. Or if it's still making the noise, might be able to isolate it or feel which actuator.

 

[xavierny25]

Many thanks Moose, I'll give that a try tomorrow and report back with whatever I find.

 

[Mektek]

Maybe leaves in the fan are causing vibration? Lower rpm = less noise and vibration.....
A bad actuator won't produce vibration since it moves at a very low speed.

 

[John in RI]

One of my failed "blend door" actuators sounded like that. (I've had more than 1 of them fail ! ) It sure sounds like an actuator with stripped/worn gears. Actuators fail independently,...... no need to replace anything other than the 1 that's giving you a problem. If you remove the lower hush panels and use a flashlight to look up under the dash housing than you might be able to see what actuator is active when the noise is audible.

 

[xavierny25]

Finally got a moment to investigate this issue further and found the culprit.
Thanks to this nifty diagram that I was able to dig up I was able to narrow it down to the driver temp actuator. It doesn't seem to hard to replace. We shall see after I have the part in hand and some free time to swap it out.

 

[John in RI]

Here's a picture of the proper indexing if you install used parts - or for anyone else that finds this thread in the future ! The main gear "notches" line up vertically and smaller
"potentiometer" gear has 2 pins that align horizontally,.... (#'s printed on small gear positioned at the top. )

Pic shows Vent/Floor actuator,.... but all of them are indexed as shown.

 

[mrrsm]

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