I went through that same problem when i first hooked up my battery and isolator. I tried searching far and wide in my car with no luck. So, i got pissed one day, and totally removed the entire set up. Next i redesigned where everything goes, and made more room. I moved everything MUCH farther away from where the power cables were, and now it's sounding great. I don't know if this will help, but i did go through the same thing you did.
