O.K. I'm trying to eliminate ground loops without an Isolator. If I unplug the RCAs from the head unit, the noise stops, so does this mean the radio has the ground issue? I moved the ground from the stock harness and went to the body with it...the noise changed pitch but didn't go away. Any ideas? I'm running 2 amps and an electronic crossover (all of these are grounded at the same spot) Do power wires (+) cause this problem ? Like the constant battery lead or remote on for the amps ? Thanks in advance.