Buzz behind the glove box?

[sarookha]

After a few repairs (added heated seats, replaced speakers, synced a key fob) there is an intermittent buzz coming from the general area of the glove box.  Every five seconds, like clockwork, there is a short buzz.  Only when the ignition is on, and not always then.  But if the car is running it is almost always buzzing every five seconds.  I took out the glove box insert, and using the dowel rod to my ear trick, looks like the right-most part in the photo below is responsible.  Part # 16137740

Any thoughts?

Edited January 1, 2023 by sarookha
added image

[2seater]

I have heard a vacuum sound from that general area in the past. I had leaking vacuum feed to the HVAC controller. Maybe sound like a buzz if conditions are right? 

[sarookha]

I'm pretty sure it's not a vacuum leak, it is precisely timed, and a makes distinct buzz.  In between buzzes, no hissing. And often happens even when the car is not running but the ignition is on.

[rogold]

You might pop the rod off the top of the module, then see if the rod will move freely left to right. Maybe something is jamming the flapper door it is trying to move. You can also turn the ignition on and see if the buzz is still there or if the arm on top of the box now moves.

[Ronnie]

You can test to see if the blend door is operating properly. that might tell you something. HVAC Blend Door Motor Troubleshooting

[2seater]

I see a photo has been added. The part being referred to is the HVAC controller. The arm on top with the horizontal rod attached is the temperature blend door and is operated by a stepper motor inside the controller. Simply running the temperature up and down with the key on should make the arm move. Inside the controller are four vacuum solenoids which operate the various air direction vents and doors. The vacuum enters through an 1/8" plastic line at the bottom of the controller as well as the four colored lines to the operators. This is visible with the modesty panel removed below the glove box.

[sarookha]

Awesome info, that explains why it has started blowing hot air whenever the HVAC is operating, regardless whether I chose heat or not.  Thank you!

[sarookha]

Replaced the HVAC "programmer", as Buick calls it, with a used part from ECRP, including a 2 year warranty.  Everything is working fine now!  I think, fingers crossed, all the gremlins are now worked out of this Reatta.  Every lamp, indicator, button, piece of trim, etc. is in place and doing its job.  

 

Thanks for the pointers and encouragement!