There are random times when there is a buzzing type sound coming from behind my radio head unit. If I change the circulation location like from face to feet, it'll stop, but may start again if I hit auto. It doesn't change with the fan speed and shuts off when I turn the heat/ac system off.

Ideas?

 

If the noise comes when changing modes then it's the air mode servo. If it comes when changing the temperature, then it's the air mix servo.
Do a search, and you'll find out how to go about fixing it.

 

Thanks! Found a lot of good info. Gonna wait for it to warm up before tackling that one.

 

Before you put motors in it, check to make sure something hasn't fallen into the fan. Pull the cabin air filter and stick your hand in the blower. Leaves in there make a buzzing sound.

 

Good to know. Thanks!