I was in my truck the other day, and while under the dash, I accidently touched a hot wire up against metal. now, when I turn my stereo on with the truck running, all I get is a LOUD hum. it I turn the stereo on with the truck off, I can hear the stereo. I have an amp running my front stage (500 watts), and an amp running the rear (1500 watts), with a capacitor. any ideas as to what I did???