Have about a 2" diameter round item in the headliner on the driver side. It looks like a speaker grille. Can someone tell me what it is and what it is used for?
Thanks

 

A little information about what you're driving will help those responding.
It's suggested you post your vehicle information in your sig, other wise we can't really give you a hand if we don't know what your truck is!

 

I'm betting he has a 2nd gen with automatic climate control.

It is the interior temperature sensor.

 

sorry bout that, it is a 98 Blazer LT and yes it does have climate control

 

nuff said i guess?

 

i have that too and sometimes i hear noise from it

 

If you hear a noise coming from it, then there likely is dust buildup on the fan inside.

 

Sweet....learned something new today.