My '48 GMC 1Ton had been converted to 12V and negative (-) ground, had a new wiring harness installed before my purchase and still uses the 6V starter with its original starter switch. The wire from the ignition switch was run directly to the positive (+) terminal on the coil without being run through the ballast resistor.
My reading here on the electrical forum convinced me to use a ballast resistor and upgrade the starter switch to the type that has an extra terminal on the switch to provide 12V power to the coil during cranking.
I mounted the new switch---I think I created a new yoga position, "prostrate man with dangling arm"---and wired it up. Upon reconnecting the battery I felt the coil heating up even though the ignition switch was in the off position. I have 12V at the battery connection to the starter and 12V at the side terminal and that can't be right. Bad switch?
I disconnected the wire from the starter to the coil and tried to crank the engine but nothing happened when I pressed the stomp button except that I could smell something getting hot!
2nd vote for bad switch?
Anyway, looking for opinions before I make a stink with the vendor and return the switch. Thanks for your help! Jim

***Update 11/24*** Things are better now! The starter switch was bad due to poor assembly. The lug for the battery cable was touching the contact for the side terminal on the underside of the switch all the time instead of just when the stomp starter button was being pressed. I adjusted the fit and everything works correctly. The engine didn't want to turn over because the starter was hung up on the flywheel. A funny sight watching my 125 lbs. rocking my dually flatbed back and forth like I was stuck in a snowbank. Old skills come in handy every now and then.
All this trouble could have been avoided if I had tested the new switch before I installed it. Lesson learned! And now I can change out a starter switch in about 5 minutes, considerably faster than the first time I did it. Jim


Last edited by Eureka Jim; 11/25/2017 3:52 AM. Reason: Problem solved