04 grand am radio help

I just got an aftermarket radio for my 2004 grand am. I've got most of the wiring down. The guy i bought it from gave me this extra red wire and said it would have to be run from the radio to the fuse box. That doesnt make any sense since the radio is already getting power from the connector. I didnt connect the red wire. I hooked it all up and it doesnt turn on. at all

Does anyone know a good place to get a wiring guide for 04 grand am radio (free if possible) or have any advice that could help me out with this.

Thanks

The red wire you did not connect is the constant power wire most likly.

Here is a link to the wire diagram for your 04'.
http://www.bulldogsecurity.com/New%20Wires/New%20Wires/Wires/pongrandam03-04.htm