Yeah, that’s what I was referring to. I remember reading years ago to NEVER leave your truck in the “ON” position without it running as it was very hard on some component and could “burn it out”, can’t remember what component it was though. Is that not the case on these trucks? It’s good to hear you did it for three hours on your truck, I’ve done it in other gas GM vehicles and the thing would barely start after 20 minutes. I hadn’t tried to see how long this truck would go for the reason stated above. Thanks for posting your experience, maybe I’ll try it.
In older cars with breaker points style ignition, you could burn out the ballast resistor if the points were closed and the ignition was left on for long periods. I don't think this is an issue with modern electronic ignition systems other than normal battery drain from any accessories.