My 1999 Ford F350 diesel starts hard when weather is cool.
You’re going to have to expand on that. How long does it crank? Did this happen last fall and throughout winter? Any recent repairs? Etc…etc…
The temp is around 45 in the morning. When I try to start the truck I have to cycle the glow plugs 10 to 20 times to before it will start. I replaced the glow plug solenoid today but it did not start on first try I had to cycle the glow plugs again
diesels hate cold weather especially when it starts to get down to the forties and some times you might have to cycle the plugs more than once espcially on decade old trucks
When it is cold I plug in my heater for the engine. I believe all the 7.3’s have a plug in heater.