reinstalling old Mazda 323 radio

My new CD player was stolen out of my 1988 Mazda 323 and I would like to put the original radio back in. Fortunately the thief did not cut all the wires. He pulled the one blue, one green and 2 white "plugs" and think that all the wires are attached. The antenna wire was not cut and seems in working order. There is one cut live blue wire with red stripes that does not have a plug and I don't know where it should go. With all the plugs in place there is power. I can see the radio display, scan through the channels, but there is no sound. I checked at a local car stero store and they did not want to install it for me. I hate driving in my car without a radio! I am a complete novice but want to at least try to fix my radio on my own. Thanks, Grandma Kay