One more thought--do ALL of the wires that came out of the single plug that went into the back of the factory deck go straight into the amp? Or do only some of the wires go from the deck to the amp? I'm kind of wondering if the amp has 3 plugs on it. 1) the plug coming from the deck, and 2+3) the normal 2-plug system I described above that would have otherwise plugged into the back side of a head unit with a built in amp. If you look on crutchfield's site under the accessories, there are installation accessories including wiring harnesses plus the picture showing the currect plugs. There's also a ton of these wire harnesses on Ebay for under $15.