I recently bought a 94 Mustang GT Convertible. Previous owner had replaced the original stereo with a JVC, everything else was still mach 460 system. Not sure what they did wrong but the only speakers working were the door and back seat tweeters. I recently replaced the JVC with a kenwood and installed kenwood door and back speakers. Still the only speakers that work are the mach 460 tweeters. I bought everything from Crutchfield so I followed step by step instructions for installation. From what I have read I probably need to bypass the mach 460 system but I'm not sure how to do this. Maybe its time to take it to a professional. Any ideas??