I scored a rebuilt radio for my 54 GMC at the Petit Jean swap meet. The seller, who claimed to be the rebuilder, told me it would work on positive or negative ground. It makes no difference since it uses a vibrator.
One of you radio guys tell me if he knows what he's talking about. He apparently used negative ground to test it (if he did) because he talked about the wire from positive and the ground to frame.
It is 6 V by the way.
