If the engine cranks but will not start, this may be caused by damaged wiring to the high pressure fuel pump. Wiring to the pump can be chafed, which causes the pump to stop working. The chafed wires will need to be accessed and repaired.
Car Problem Reports
Ford F-350 Super Duty Engine Cranks but will Not Start - Diesel
Ford F-350 Super Duty Problem
Engine Affected: 6.4L V8 Diesel Turbo
Visitor, 2008 Ford F-350 Super Duty, 6.4L V8 Diesel Turbo, 110,000 mi
just died in the parking lot, to find out wires were chaffed from factory and needless to say this factory problem cost me $2500, go figure, way to go ford.