Just hooked up my old head unit (Panasonic CDqf-802) in my brother's 97 Explorer. Head Unit was working fine when I took it out of my car about two months ago. Got it hooked up, everything works as far as power, ground etc., and sound comes out fine on radio. When you switch to cd though, it'll count through the seconds on the tracks, but no sound will come out. I am hoping this is not an internal radio problem , and instead has somwthing to do with a wiring issue. Any ideas? thanks, Mark