Jerry,
A '58 is not a rig I'm familiar with..Bill (red58) knows these inside and out. My guess would be, if that is the stock switch, that it should have ON-OFF-ACC positions.
The starter switch will have a large lug with BATT positive connected to it. It should also have a #10 or #8 wire attached to the same lug which is output from the charging system. If you do have a ballast resistor that is functional and you do have a stomp starter then you have to have some type of bypass system to make that circuit work.
With a ON-OFF key switch and stomp starter, the only way to make the ballast resistor work is with a bypass terminal on the starter switch. This isn't connected to the large BATT lug but rather to a small terminal hanging off the side of that starter switch.
I don't know how it could happen but you need to make sure that small terminal has NO power when the truck is sitting dead in the driveway. I'm not sure if the wire you mention that runs back to the ignition switch is from this small terminal, but I would find that strange. The ultimate destination for a wire from that small bypass terminal is either coil + or the coil side of the ballast resistor.
Stuart
