Installed clarion dxz845+profile 1040 amp 4 channel. When the 4runner is running i get ahiss whine with both front and rear rca's connected if idisconnect one of them does'nt matter witch one the niose is totally gone .I have the amp grounded to the fender well in the rear compartment.I tryed 80 dollar rca 's same thing.Any stereo guros out their please help.