I realize that this is an old forum, but Frank if ur still checking this thread. I have a 53 Chrysler imperial semi- automatic, and Ime 99% certain thatbus is the relay that is bad as there is always continuity between the Neg Battery post Large bolt and the center smaller post going to the posistive on the start, meaing no matter what you do the starter is constantly trying to engage even with the key in the off position and yes this is a 6V Postive to the frame (Reversed Polarity system Commonly and incorrectly refered to as a positive ground) my Question is this. how can I find a replacement relay. the one in the pic you posted looks right but no longer available. Also Napa has some option that go back to the sixty but they don't have a voltage rating. I am uncertain if one designed for 12v Neg polarity would work with a 6V postive poliarity system.