Hi, I have a problem with my friends 2002 Monte Carlo radio. I tried installing a aftermarket radio in her car and i have no sound. i found out that you need to jump the ignition power from the radio directly to the ignition and the radio turns on no problem but i have no sound what so ever comming from the speakers. after giving up i then put her stock radio back in and it dosent work either. the radio lights up but there is no display and i cannot control the radio. could this simply be a fuse? i do not have the car at my house on a regular basis so i have not been able to check the simple stuff out. please any suggestions is of great help! thanks