99 escalade bose into pioneer deck

Hello all, I have a little issue here and I am starting to get a little restless so I figured I would try the question on some professionals (and some backyard warriors too). I have a 1999 cadillac escalade with the bose deck and speakers. I am interested in finding all the stuff I need to integrate a pioneer cd deck into the dash. I already have the installation kit: space filler, ant. adapter and wire harness, but I need a few more things.   I have a 6 disc changer in the center console, and onstar. My question is "where do I find the onstar converter (a good one) and an adapter to run the stock gm wire into the back of the pioneer deck and use the changer"? The onstar thing isn't to bad, but I can't find the GM male harness to Pioneer aux male adapter anywhere. Can I make one? I hope someone can help me. Thanks, Mike

You won't be able to use the factory CD changer with your Pioneer deck. They are not compatible in any way. You can start with companies like Peripheral, Metra and Soundgate to find the correct modules you need. You will need one to supply the Onstar with an amplified audio output and speaker. You should also find one to mate your new deck with the Bose amps in the truck.sparky