My blazer came with onstar but the analog service was stopped soon after, or maybe I just had no right to use the service, but now it's useless. I'm wondering if people have tried playing with the firmware and getting a custom radio transmitter or something? Can I modify the buttons in the mirror to do anything else? BY the way where is the controller for the mirror part of onstar? I removed the modem but the mirror onstar still "powers on" every time I start the vehicle, I'd rather just shut it off permanently to stop drawing power

 

Fancy paper weight!! I don't know about anything else though. I know when the systems went digital there was a recall for the units in the full size trucks but not sure about S/T trucks. I will have to look that up.

 

Update on Onstar: the special policy for the unit in your vehicle expired in 2008 and it was to deactivate the service only.