2005 Gmc Sierra Cre Cab

[Stine]

Ok....right above the driver side seat, in the headliner, there's a round vent like, thing...for a lack of better term. What is it and what is the humming sound I hear coming from it? If I put my hand over it I don't hear the hum so I know the sound is coming from it.

[VMax2007]

It's a fan. It's the temp sensor for the Automatic Climate control system.

[Stine]

Why then am I now just hearing the humm....have had the truck for over a year and never noticed it.

 

By the way, nice truck.

[VMax2007]

Why then am I now just hearing the humm....have had the truck for over a year and never noticed it.

 

By the way, nice truck.

 

Thanks!

 

Common problem (according to what I have read on here), have your dealer replace it.

[VMax2007]

Well, it was right around 0 deg F all day today and I started my truck using the Remote Starter. But it only ran for a few minutes before I got in so it was not warm yet. I put the key in and it switched to Auto Climate mode (normal), but when it did this, the little fan above my head starting making a nasty noise. Not just a hum or slight tick, it sounded like a playing card in bicycle spokes. I said a few choice swear words and kept driving. It completely went away in about 3 minutes once it warmed up a bit. I do know that there is a TSB for this, but my concern is that it will only do it on severely cold days and that will be tough to get diagnosed. For any of you that have had this problem, did it do it all the time or was it temp dependant?