Wikipedia says this The electric charge flows in a constant direction, distinguishing it from alternating current (AC). Well, if it flows in one direction from the battery, how can any other components be affected? The power is flowing from the battery to the ignition module, not back to it. So it's my understanding that the radio system will never see any interference this way. Now if the ignition module or spark wire was near, then yes, I can understand. Am I wrong on the theory of the dc voltage coming from the ignition battery? I'm not saying anyone is wrong, just reasoning on the matter, thanks Randy