So as I'm driving my 90' SC for the first time, I realized that it has a really high pitched ringing sound through the speakers. It gets worse when the revs are higher. The car came with an old aftermarket Denon head unit in which you can remove the faceplate (and in turn powering off the sound) with a button. When I took the faceplate off, the whine stopped. I assume it's alternator whine. But I'm not sure where the culprit of letting it through is. Is it the head unit since it goes away when it's unplugged? Or is that just breaking the circuit, stopping the whine? I'd like some advice. Oh and I do have the JBL premium sound if that matters. Have you guys ever had this happen before?
Thanks
Thanks