Vent noises

If I have my vents in the upper position, I can hear a noise that sounds like the vents adjusting themselves every couple of seconds. I'm assuming it's the little motor that switches the air flow from upper to upper/lower to lower. Doesn't happen when it's in any other position besides upper only. Happens whether the AC/Vent is on or off.

Any ideas why this would be constantly trying to adjust itself?

 

I have a similar noise, not sure if it has anything to do with the vents, but it just sounds like electronic whirring noises?

 

adjust your temp setting to either full heat or full cool and see if it goes away... I bet it is the blend door trying to maintain temp and is constantly adjusting to maintain your desired temp.

 

Coming from passenger floor board, my kid says it sounds like a mouse squeaking? Like Glamisman said, turn to hot if it goes away its that little black blend door motor under the glove box. I have seen a write up either here or somewhere else in the past on how to rebuild and fix it.