GenVibe - Community for Pontiac Vibe Enthusiasts

I found 3 wire plugs in my car stereo Vibe 2003.First one is for antenna,second is 24 wire plug,and I can't understand for what is the third plug that has just one black wire inside.

I assume it is the plug at the far end? It is for the Aux (ether a CD changer or XM radio)I think that black wire is a dummy/place holder if you don't have ether of those. They make a Aux/iPod adapter for that plug so you can use a mp3 player