ok......if you unplug the rca's at the amp does the noise go away?
if so pull the radio out and take a piece of wire and hook one side up to the ground shields on the rcas , and the other side of the wire you want to touch the chassis of the radio, it'll either get louder or softer, if noise goes away secure the connections and you're done.
if not try connecting it to the ground wire of the radio.
if not then try only having the center pin of the rca connected to the radio and the ground shield not connected to the radio (barely plugged in) if this fixes it then either carefully strip and disconnect the ground shield of the rca and secure everything up....
what we are doing is redirecting the ground path of the rca's to where it won't be picked up by the amps preamp section. you're in good hands......we'll figure it out
