2004 F250 Super Duty with tow package. Cranks but won't start. Over the last few months it would start and drive fine about 50% of the time. Now it cranks but won't start. Dropped spare tire and crawled under it expecting to see the fuel pump driver module on the cross member but it isn't there. Ideas?

 

Not supposed to, the truck never had it.

 

That would explain it.

 

Yep. The Super Duty trucks first got the FPDM for the 2005 MY for the gassers, at least. Don't know if the diesels ever got it or not, they're not in my experience bucket. You didn't specific your engine.