what's wrong with my radio, 05 sunfire

In vehicles with class 2 data bus; you really should use an aftermarket harness. There is no switched ignition wire in that plug. I would reconect those wires and go buy the proper plug.  I know that they are a little pricy; but you could do SERIOUS damage to the cars electrical system. Not to mention your cars computer.

I would go back to the proper part installation before it's too late.

David.

There are 2 kinds of harness that you can buy for your car. There is the genaric harness (my shop uses a Metra 99-2003) that will work, and retail is right around $22. You'll need to run a new switched accessory wire to your ignition harness, and you're going to lose a numer of features. You're RAP feature, door chimes, warning bells (keys in ignition, lights left on, etc), change oil light, and you'll also generally throw a code on an OBD-II scanner. You're second option is to go with a harness designed for a class 2 data system (my shop uses the Scosche GMLAN2SR harness). Theses retail around $110, yes you can find them cheaper at places like wal-mart, but keep in mind that you get what you pay for. This will get you a switched accessory without running a new line to the ignition, allow you to keep all your chimes, RAP, warnign bells, etc.