Thanks for all help.bit appears to have been a relay switch behind the engine next to fire wall. It had a pin plug the snap in and two wires on each side. It was bad.
It turns over, 6.5 liter v8 diesel but only get a whitish smoke coming out. In warm weather starts fine. Need help, think it's the fuel injectors going out but not sure. Replaced three of them about four years ago. Has over 218,000 miles on truck.