From what you are saying ,it sounds like you may have a Amplifier problem... Radio system dead.. On most sedans the amps are in back of the rear seat one on the left and one on the rt. they are small BLACK BOXES... This problem will drive some auto electrical techs. mad . Looking for a short In the antenna sys. and even in the doors where the speakers are....."assuming you have a 6 speaker system...." Look at the AMPS after you remove them. Most of the time you can smell if it has been burnt..or see where it has been hot (shorted out) If that is the case . Look for used ones or have it repaired at your radio repair shop (In the NE GA. )area ATLANTA AREA . I Have a man who repairs these for about 1/3 the cost of new ones .Check it out . let me know if it solves your problem.