buzzing speaker phone 2001 Tahoe

The speaker above my head in my 2001 Tahoe buzzes when I crank the truck. Its seems to be more evident when it is cold outside. I do not use the On-star service - if that matters. What could cause this buzzing and how can I stop it? Thank for any help with this!

I have that same problem!!!! Ive asked a few people and they tell me its normal, and it will always do that. Its so F%@*ing annoying.....Sorry I couldnt be more help....

i had the same problem on my 01 tahoe. On-Star likes to put their junk in you vehicle, but dont want to deal w/ any of the problems it causes!
Good luck

I saw somewhere that it is actually a small fan used for the climate contol temperature that is making the noise. Supposed to just replace it to fix it. Mine does this as well.

Don't know how to replace or how much it costs though???

Damn, a small fan?! I thought it was some OnStar stuff! I get a buzzing too, but not from that speaker/fan. But then I have an 02, and I replaced the deck. Apparently my buzzing is from a bad ground (which is understandable, since I left the ground pretty long and the grounds from the TV/Deck and amp are probably inconsistent...)
Did any of you guys replace your deck(s)?

The speaker above my head in my 2001 Tahoe buzzes when I crank the truck. Its seems to be more evident when it is cold outside. I do not use the On-star service - if that matters. What could cause this buzzing and how can I stop it? Thank for any help with this!
I have the same noise. I personally think it comes from onstar. Now the little speaker at the drivers head is the source. I need to pull off the cover and disconnect the speaker wires, that will stop it. But the cover doesn't want to pull off. Any luck with yours?

Is this that little 1 inch round speaker looking thing in the headliner? If so, I have the same problem in my 99 blazer, and I don't have on star.

I had the same problem with our 2002 Tahoe. It was noisy only at startup in cold weather. (Sounded like a lawnmower) I asked about the problem at the dealer when we took it in for service, but they said they had no idea of such problems and they didn't think there was anything in that location that would make any noise. Finally, after satisfying myself that the noise definitely was coming from that area, I got brave enough to take some moulding loose and pull down the headliner.
What I found was that the Onstar speaker unit has a cooling fan on it. Apparently the bearings in the fan had gone bad. Since I don't use the Onstar, I just disconnected the wiring from the unit. End of noises!

Had this same problem on my '03 1500HD. Especially in cold weather it would buzz like crazy and drive me nuts. I did some research and turns out it is the "ambient air temperature sensor" for the computer climate control. Guess it takes readings of the cabin air temp and then adjusts the temperature if needed.
I also thought it was part of the onstar system, but the actual mic/speaker for the system is a black thing on the left side on the overhead console, atleast thats where it is on my truck. I ended up removing that sensor in the headliner and picked up a new one on ebay about a year ago, haven't had any noise out of it since. Just my :2cents: