Diesel Bombers - Early 04 6.0 Diesel Ford F250 Superduty Crank no start problem

Hello, I have a Early 2004 F-250 Super duty 6.0 Diesel Lariat crew cab truck. I have had nothing but problems with since i've purchased it.

Just one day went out to the tried to start it and just would crank and crank and crank until the battery died.. I haven;t really put much time and effort into it because ive had another vehicle but now that vehicle has #### the bed. so I really need to get this running...I dont have alot of money..so im trying to diagnose it now..before i bring it to a garage.. to save a little bit of time and money..

I've recently purchased the scan gauge 2, and ran the codes for ficm,ficm sync ipr duty cycle, Icp and Icp Voltage....

The ficm and ficm sync both ran the right numbers at idle and at cranking..id figured since i've already replaced the ficm twice recently.

The Ipr ran normal at 14.2 or .8 at idle and when cranking hit 84.7..
The ICP PSI at idle was at 0...and when cranking stayed at 0
The ICP VOLTAGE was at .11 and while cranking fluctuated between .08 and .11.

I know the Icp needs to reach 500 psi to start..so i know theres a problem with that but i dont have a clue why no psi are reading...does it sound like I need to replace the Icp, and pigtail..or..does it have something to do with the Ipr?...

any help would be very much appreciated...thank you!