Random no start no spark

This is my grandfathers truck that I have been driving. When I borrowed it from him he told me of the only known issue, that issue is that randomly it will not start. I recently went to go get lunch, pulled into the parking lot and shut the truck off. It didnt start after that. Last time it did it to my grandfather it shut off, he called a tow truck and had it towed. When it was on the back of the tow truck the driver tried to start it and it started right up like nothing had happened. I replaced the distributor last night to see if that did anything. I have power from a pink wire from the harness to the external coil, but nothing with the key on from the dis. There is no spark from the coil or end of wire. If you could point me in the right direction I would appreciate it.