cd changer installation on 99 323i e46

[omarhr]

I need help, I just bought a used cd changer for my 99 323i and I found the wires in the trunk and plugged it. The changer is not doing anything and the radio does not appear that it even recognize that there is a cd changer plugged in. is there any steps that I must follow in order for the radio unit to recognize the cd changer? also I found the wires that go to the changer it was to sets, I also noticed that there is a round input right next to where the wires go, is there a third wire that needs to be connected or just the two harnesses.

[FCPGroton]

This happened to me once and it ended up that the cd changer was not getting power so the head unit did not know it was there. Check to see if the inline fuse has gone.

[BMWer14]

Anybody need one of these...I have one for sale...6 CD truck mount changer from a 323i.