10 volt ref is for the steering wheel controls. The radio operates on 12V.

Here is yet another
https://www.chevyhhr.net/forums/audi...-needed-25414/
Here is a pdf it is from a 2009 SS, but they are all the same
Attachment 47788
Note there are 2 voltage inputs #1 is the switched input and #2 is the light and memory.
If the wiring diagram doesn't help you, I don't know what else can be done on the interwebs.

Any radio, regardless of manufacturer, that requires a data connection to the car will not operate without being connected to the car's BCM. This info came from a local company that repairs car audio. They told me they have a device that can simulate these signals, but it isn't cheap and isn't available to the general public. I contacted them when I had a really nice factory head unit that I wanted to use in an older non-computerized car.

@mongo is right. I forgot you were wanting this to work outside the vehicle. The key needed that the radio seeks can be derived through a circuit using a chip. It only needs to be able to handle a mild encryption key. I would think 128K would be good enough.

I just use my old Bose Wave the cd player doesn’t work anymore but the FM does, sounds pretty good. Plug and play!

I found an old good quality stereo receiver at a thrift store for $15.
https://cimg0.ibsrv.net/gimg/www.che...3f7c129c9a.jpg

Thanks mongo. I did see one of thjose units searching around. They were $99.00. Must be what you are talking about. I will have to chase down a circuit. Should not be too hard to make.

Thanks again. That is what I needed.

Yeah Greg, I am searching for circuit. Thanks.

Just grab a cheap single din deck somewhere with USB or Bluetooth. Then find a cheap computer power supply and use that to power it. Or find a cheap receiver at goodwill. I found a denon for $30.

I don't think it's worth using it. It only has 3.5mm and maybe USB.

Here's one, but out of stock. They have dropped considerably in price in the last 5 years

https://www.etlweb.com/emulador-de-vin-de-radio-gm

Here's an Arduino hack for adding a camera, but the same principle would work for pretty much anything canbus or GMWLAN related.

https://tbruno25.medium.com/car-hack...o-b391fcea11f1

At $150.00 for the one solution, you can get a pretty nice old schools home stereo and a tank of gas and still maybe a nice lunch! Check out your local thrift store