95 E36 M3 Headunit Install ?s

[M POWER 7]

I recently purchase an E36 95 M3 and I absolutely adore it. I wasnt happy with the factory head unit so I pulled it and put in my JVC MP3 unit from my old car. When I took it out of my old car it played CDs perfectly fine. I purchased a harness from a car audio shop and put the head unit. The Radio works wonderfully, but it wont play CDs at all (MP3s or CD-Rs) Im wondering if the old factory Alpine changer has anything to do with it? Has anyone experienced similar problems? Your time and consideration is greatly appreciated.

Thanks
Chase
M Power 7

[M POWER 7]

I did some reading and found out about the blue wire business. Should have searched more. Thanks

-Chase