Looking to add an OEM DVD unit... HELP!

I am looking to add a Chevrolet OEM DVD unit (Panasonic) to a 2003 Trailblazer. The vehicle did not come with the DVD system originally but it seems like adding one should not be extremely difficult. The donor system came from a wrecked Trailblazer. Here is the problem... It will hook up and the DVD player gets power but the display will not power up. I get no audio or video. I have been told that GM utilizes a security measure which effectively "marries" the DVD system to the vehicles audio components making it non-functional if moved from the original vehicle. I don't know if this is accurate but even if it is I am assuming that there is some means to bypass it. I am looking for anyone who has made a successful installation of this type or someone with a little technical expertise in this field. Any help would be appreciated.