Annoying noise - can't figure it out

[shifty]

Mystery solved! Unlikely answer is in post #7

Here's the deal, before you say anything, you should know things:

- My hot/cold blend door motor is operating fine and quietly.
- My recirc/fresh air door motor opens/closes quietly when I push its button.
- The recirc door motor is close to the sound source, so I unplugged its power to test, no change at all.

That said, got this annoying noise I can't figure out for the life of me.

- Happens most when I hit hard bumps, turn hard or take bumpy turns.
- Sounds like it's coming from behind the passenger airbag.
- It reminds me of a toy gear winding back/forth, or a zipper being zipped back/forth.
- There's also some rattle involved.

Any thoughts on what could be causing this? It's making me a little crazy.

I'm open to the idea it could be one of the motors, I know they break, plastic gears crack. But all the climate door motors seem to work well, quietly. I don't get heat all the time. Recirc button and door works great to change modes. Good replacements are expensive!