Help! Wiring aftermarket radio in a 2002 Chevrolet Cavalier?

[kyle]

I have a 2002 Chevrolet Cavalier which I am installing an aftermarket radio, but the wires running out of the car, do not match up with the aftermarket radio's wires. I have cut the wires on the factory radio wire harness too short, so I was going to wire up the corresponding wires, but ran across multiple problems. There are two black wires which I am guessing are both ground wires? and a purple wire, which I have Googled into being a BCM wire? Also, there is no 12v accessory wire coming out of the car? How could the stock radio have worked without always being on and draining the battery? Could somebody please help me with how I can wire this or something I could buy to complete this aftermarket radio installation?

[AeroD]

First off, NEVER EVER CUT THE PLUG!!!!!!! The wiring harness for you car cost $10, instead of the hastle your now going thru. You are going to need a multimeter, and have to go thru each wire in the harness. I would use the factory plug, as a guide as to which is part of the radio harness and which isn't.
If you can't figure it out still, you will need to take it to a shop, and pay to get it fixed, usually around $65/ hour and up.
Good luck!