My F250, 6.0 ltr, won't start when the motor is warm, What do I have to do?

Check the Glow Plug Relay (Item 8) in the link below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281

My 2006 Ford F-250 6.0Ltr does not start when engine is warm