Just replaced the battery in my '98 ZX2, and now there's no sound from the stereo. All the lights and controls work--time, radio station, volume, etc., but no sound. From what I've found on the rest of the internet, I think I either need to find and input a code or possibly replace the speakers. All fuses under both the hood and the dash check out. Any advice? If it is the code, how do I get it?