aux input on delco cd

I am adding a aux input on the factory am/fm/cd radio in my 92 cavalier z24, i need to know which wires are the audio inputs from the cd unit to the amp inside the radio? id appreciate any help/schematic to find the correct wires, should be a left + and a right + from the cd unit to the amp

Purchase one of these http://www.radioshack.com/product/index.jsp?productid=2062620  and one of these, http://www.radioshack.com/product/index.jsp?productid=2062452  You will need a few feet of small wire to make a ground and a probe to attach to the plug.  With the radio out of the dash of the vehicle and the CD mechanism removed (only if you can not get to the wires of the mechanism that go to the deck)  Ground the ground wire of the plug to the chassis of the radio.  With a CD playing in the CD player and the radio volume all the way down.  Volume up a bit on the amplified speaker, touch each connection on the harness that connects CD mechanism to the mainboard.  2 connections will play audio out of the little speaker.  Those are the 2 signal wires.  If you still want to use the cd player, you will have to wire a switch to switch between CD and Aux In.  Let me know if you need help with that part of the project.

The level coming out of the CD mechanism is probably not hot enough to hear on a set of headphones.

if not then i will get that amp from radio shack or even computer speakers i have with its built in amp would work i think

1 more ?    How do i find the wire that tells the amp to turn the radio part off when a cd is inserted, i know whichever one it is needs to be hooked up to a switch that grounds it