whine noise

Hi I have a 95 Jeep Grand Cherokee Larado. In it I have a kenwood kvt-815dvd indash monitor, kicker 500.2 and a 600.4. When I have the ignition turned to acc or run and the volume all the way down to 0, I hear this high pitch whine noise coming through the front and rear speakers and the sub has this hum to it. When the jeeps started then it's a really loud whine and the sub has the loud hum that goes with the sound of the engine. I thought it might of been the ground, so I ran a 4 gauge wire to underneath and attached it to part of the sub-frame system, also the ground is ran to a distribution block and has 8 gauge going to the amps. Before I had the head units speaker outputs playing the speakers and they sounded fine, except for the sub.

Try replacing the noise filter at the alternator if it has an external one. They are pretty cheap and may help. I had a similar problem on a GM vehicle and that was the fix. Good luck.

Here's an update on the situation. I hooked up an rca from my radio to my friends amp, before I even had a chance to turn on my radio there was a whine noise coming through his speakers. So then I ran an rca wire from his cd player to my amp and it played fine, no noise. So now i'm thinking it's something to do with the radio's brain box, seeing as how there was feedback being produced without the radio even on.