rca signal is ac, but it does normally share chasis ground, check you amps ground, check you batteries ground, check you frames ground, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, gounds, it almost always a bad ground,


i bet your radio has a bad ground and is tring to ground thru the rca's