Please confirm your GMC is wired POSITIVE ground and you know that.
Yes, it is a positive ground system and I am aware of it. It's an assumption I made because the red battery cable goes to the chassis and the black cable goes to the starter. There was no battery in the truck when I bought it, but, I was looking through the photos I took of the truck when it was at the PO's house and there was a 12v battery sitting on the driver's side floorboard. I don't know if they just stored a battery there by coincidence or if they were using a 12v battery in the truck. Two of my friends that have owned these trucks in the past said it looks like a 6v system, generator, etc.
