AVIC-Z1 install woes

[Lucifer]

Spent 8 hours installing a Z1 to only run into a problem at the end Tapped the brown wire in the drivers pillar for the reverse wire. Got lucky and the VSS wire was in my radio harness Used a Metra GMOS04 wire harness because it has the Onstar and chimes built into 1 unit and you can control the volume of the chimes, (turned way down). Also had to loop the 2 purple wires in the gm harness. Only problem now is that when the key is in accessory mode, I don't hear any music from the stereo, but Onstar still works. As soon as I open the door and the door chime starts ringing, the music from the stereo comes through. As soon as I shut the door, no more music. With the key turned to on, I don't get anything even with the door opened, but again Onstar still works. I'm going to call Metra in the morning, but was just curios if anyone has any ideas on this. Checked wiring 4 times, and all seems correct. Pretty strange if you ask me.