Today was was working on getting my cassette deck hooked back up in my car (I'd disconnected it during a "find the short" session a few months ago). Anyway, after finding some instructions I learned that there are three wires involved with the power..
Yellow -- hooks to always hot pole
Red -- hooks to accessory pole (so it's off when the key is off)
Black -- Ground.
I thought this would be self explanitory until I hooked up the yellow and red and the radio came on. So the question that I post is whether the ground wire is just to provide a really good ground (and the radio grounds through the shell like the really old 1 wire radios) or is this a bad sign?