I am still a bit confused on the wiring diagram provided in this forum. The installation guide says the black wire goes to ground, not -12VDC (com). I often get ground and common mixed up, but I believe in most cases they are different, so is pin 2 literally tying to ground (as in chasis ground), as indicated on p.22 of the installation manual, or does pin 2 wire to -12VDC (or com) as the revised wiring diagram (in this forum) is suggesting?
Another question: what potential problems may caused by not grounding the radio chassis? If so, then does pin 2 get attached to this?
Thanks.