My '94 Bronco has a lot of problems in the sound system. When I got it, it had this built audio system in it which has a lot of crap in it. Anyway, the radio has a lot of alternator whine and crackling to the point where I can hardly hear the music. I stuck a couple of those Scosche audio noise suppressors in, they did nothing. I stuck them in behind the radio and now they kinda suppressed a little bit but not too much. A friend said to look at the factory noise capacitor and so I did and it doesn't appear damaged. I swapped in a different capacitor and it still doesn't work. Any suggestions as to how to get rid of this problem? The previous owner and myself took it to a few different sound shops and they couldn't figure it out. Thanks.