I got a used amp from a friend of mine, it worked just fine in his car. I put it in mine and the protection light keeps on flashing. According to the Alpine manual I flooded RCA ground, wtf does that mean ? and how do I make my amp work ? I have beem bass less with 80hz high pass xovers for the last 2 months and its driving me nuts. My computer system puts out more bass than my car. I am not some big stereo nut when it comes down to it, I'm more into mechanical parts of my car than bumps. HELP !