I didn't even think about looking in the "starter and charging system" in the Hanes manual. Sure enough, purple wire goes from ignition to solenoid.
We had to hot wire the 90 square body Burb one day; battery was going bad so we bought one at Walmart and tried to install it in the parking lot. That truck had most of an aftermarket alarm on it, and that went crazy as long as the battery was hooked up. So we had to wire around it to get the truck started. You get a lot of dirty looks in that situation.....that sob was loud! But I remembered him talking about the purple wire, and how he'd set up a kill switch on that 55.