Onstar

Does anyone know where the mic is for he onstar in a 2007 GMC Tahoe?

The first place I’d look would be the owner’s manual.

It’s in the rear view mirror.

Yep its in the mirror. My Chevy dealer first started offering Onstar right around 1998 and it was an entirely dealer installed option (very much like an in car cell phone install).In these eary installs the technican (me,but really I was just a mechanic) could put the mic any where I wanted but after about 18mths of Onstar installs they started comming from the manufacture with Onstar pre-installed. Our Sales Dept. would pay me 5hrs labor to install an Onstar unit. Having days filled with the installation of accessories like this has pretty much ended. I can remember 1997 as the last time I ever installed rear air in a Tahoe. Can you imagine a Tahoe without rear air? Some may say 1997? that is ancient history, but to me it is like yesterday. I find many questions on this forum to be right from the years I was most heavily involved with Dealer operations 1995-2005.

Thanks so much for your help. I will check that out when i leave from work. Also do you think there may be a problem with the mic if i can hear the onstar operator but they can’t hear me.

Again thanks for your help in letting me know where the mic is.

What I would do is give Onstar a call (cell phone or land line) and tell them what you just told us,you can hear the operator but it does not seem she can hear you. Onstar has a good bit of diagnostics in it and I just bet they can tell you if the mic is detected and what level of signal is being seen. Did you give the back of the mirror a look over and see if a wire is hanging loose?