1987 300sdl. Ok have original radio in car and working great when it went in for suspension work. Two weeks later (one week job...ya right) now car has no sound. Dial lights w/ correct radio station displayed, antenna goes up but no sound from volume at all. Have checked obvious- antenna connections, fuses, fader etc. Radio acts like the antenna is not found, as seek/scan gives no station for am or fm. Sounded great before shop..any ideas?