Truck not starting

Same thing happened to my '83 s10. I finally traced it to my ignition on steering column. I can turn the key on and it powers everything up. Turn it to crank the truck up and nothing. At that point I just said screw it, weng to Autozone and paid like $10-20 for a momentary contact push button starter switch and mounted it in the dash and ran a 2 conductor to the engine compartment. Hooked one lead to the positive post on the battery and the other to the starter. Haven't had a problem since.