I have an '08 Tahoe and I need a diagram that shows the colors, position, and purpose of all the wires in the two connectors, black 14-pin and purple 16-pin. I especially need the connector for the XM unit. What I'm looking for specifically are the two wires for the left and right audio from the XM module behind the glove box. Anyone know? I plan to tap into them with a 1/8" connector and make a second aux input for my sirius pnp unit. The main one on the front of the radio I'll use for my mp3 player.

 

Well, I'm getting closer, I have ID'd the wires I need out of the XM unit. They are as follows: Left audio neg. is the tan/white in 1, left audio positive is brown white in 2, right audio negative is dark green white in 3, right audi positive is grey in 4. These are out from the XM unit under the right side of the dash.

I'm trying to use those 4 wires to "hijack" the XM audio signal and use it as a 2nd Aux/line-in. Anyone know how I would combine them and wire-in a 1/8" female connector? I tried left and right positives for left and right on the audio jack, then I tried combining the 2 negatives and attaching them to the "common" on the jack. It works, audio comes out of both left and right, but the sound isn't *quite* right. It sounds WAY better via the aux in the front. I think I'm close, just not quite right. Anyone have suggestions??