My 09 XLV Gravity is getting feedback noise thru the speakers when the engine is running even with the stereo OFF. I also get feedback noise from my wakeplate motor when I'm adjusting it. Same thing... doesn't matter if the stereo is OFF or ON. When I turn the Stereo switch On and OFF is stops if for a few seconds but the noise comes back. I know this is a grounding problem but not sure where to start troubleshooting. If anyone's had this problem before, please let me know the quick solution.