Car Stereos: Radio Powert, 2006 chevy trailblazer, vehicle data bus

Question
Hello,I have a 2006 Chevy Trailblazer with an aftermarket radio installed. Every time I open my door the radio comes on for a brief second then turns right back off with no key in the ignition. I replaced the wiring harness thinking that was the problem and it was not. It's causing my Onstar to malfunction when there is no power to the vehicle, the onstar reps. can not communicate with car.. Any Suggestions.

Answer
Hi Leon,

Which adapter are you using to make the new head unit work with the vehicle's data bus system?

It really sounds like a problem with the adapter.  All of the adapters for GM Class II data bus systems work by communicating with the vehicle data bus, and generating an accessory power output to turn on the after-market head unit.  Also, the adapter is solely responsible for keeping the Onstar working in the vehicle; it doesn't need to turn on the new radio for this task.

I'd suggest contacting your adapter manufacturer's tech support for assistance; or just try a different adapter from another manufacturer.

Good luck!

Brian