my 2004 f350 6.0 diesal dually wont start it turns over but wont start

Glow plugs getting energy to glow? Don't you have a light indicating the glow plugs are engaged?

mix 1 part gas 2 part diesel in a squirt bottle, admit in intake after air filter somewere a few squirts, or spray at removed air filter, while cranking, if start happens you know its a fuel related 95%, like ///prime////glow/////rpm on crank ----water-filter drain

I dont think i have seen a light like that just the little squiggly one that you have to wait for it to go off before you start it

squiggly is from glow timer

that's it! choo choo you guys are on the right track, now is it coming on, then cycling through?

Could be the fuel injection control module they are known to fail, you could have a high pressure oil leak causing the injectors not to open. Those are two of the most common issues ive seen. You need a scan tool to check the FICM voltage if it drops below 45 volts then you have a bad ficm. you can also check injector control pressure (ICP) it needs to be aleast 500psi to start. If its not you could have a high pressure leak or a bad injector pressure regulator. It could be a number of other issues but those are two common ones.

...whew, we have a GURU who knows about diesels. hooray....kudos~