I picked up a 90 SC 30th anniversary three weeks ago. The factory radio (premium sound) doesn't work right so I want to put a new stereo in it. I got the old one out but can't get the new one to work. I have power but no sound. Any idea what special adapters I need? I don't believe it has JBL but I'm not sure and don't know how to verify. Any help will be appreciated!