alpine list thier manuals on the website. just google alpine and find the official website. manual is in the support section,btw chasis ? u mean ground? that's always the black wire. also the aux i'm not sure i never owned a alpine but it should be in the book.
The aux is for outside sources like Ipods or MP3 players. I don't know about Alpines, but when I plug one into my Pioneer, it automatically turns on the aux and starts playing.