Periodically, for several months, either the truck wouldn’t start or would shut down with no warning while diving. Now, it will not start at all. The symptom of the starting issue: the “wait to start” light would come on, but flicker off immediately. Until recently, the truck would start when the light remained on for several seconds. Now, I cannot get it to remain on and start. It is not the glow plugs or glow plug controller. Both have been tested or changed. I did replace the main ground wire to the starting motor. What should I look at next?
I would start with the fuel system. When a diesel is running the only way to turn it off is to turn off the fuel. It could be a bad fuel pump,fuel filter or whatever controls the fuel on your truck. I would bet its what controls the fuel.
It’s not the fuel pump, filter or injector pump
The glow-plug light is not acting normally. Find out why…How many miles on this vehicle? Compression test?