Keeping the 6 changer with new stereo 1.8s se

[smittysmop]

I didn't see this topic, or i am just poor at searching. I am installing an aftermarket headunit and speakers/sub in my 1.8s special edition sentra. I wanted to keep the 6 cd changer and link it to my head unit since it supports a changer. I found wiring diagrams for the sentra, but none that mark which wire is to activate the changer. Anyone know?