Dead Radio -- Need Help

I have a 1996 Grand Prix. The radio went dead recently. When I pulled the factory stereo out, there was a red wire and a yellow wire coming out of the plug, unattached to anything else and I can't tell where they should be spliced into. I've tried putting another stereo in and it just doesn't work, so I'm assuming it is the wires. Can someone help me figure out where these wires need to go? Thanks.