These guys have you on the right track.
-- No tach movement while cranking = bad CPS (get one from ford or international. No on else seems to be able to make on that is worth a crap)
-- Does the "Wait to Start" Light come on when he turns the key on? (No WTS light = no power to the PCM (powertrain control module. Usually a bad Maxi Fuse #22 under the hood)
If neither of those is the issue:
-- Do you get any smoke out the tailpipe while cranking? If NO, take the IDM out of the truck and shake it. Listen for water inside it, they have been known to get water in them and then fail.
-- Make sure your starter and batteries are in good condition. These 'strokes need a lot of speed to get them to start and if your batteries are weak, or your starter is getting old and slowing down, that can make them difficult to start.
--How cold is it right now where your brother lives? If his Glow Plugs (GP's)are not working he may have difficult time starting it. To check the GP's, use a meter or test light on the Glow Plug Relay (GPR). WHen you turn the key to the "on" position, you should have power to BOTH of the big terminals on the GPR. If not, you likely need a GPR.

Here is a picture of the IDM:



Your GPR won't likely look like this one, but it should be in the same location and look like a starter relay.

One more easy thing you can try if none of that works is to unplug the Injection Control Pressure sensor (ICP) that first picture shows the ICP as well. If the truck starts with the ICP unplugged, The IPR might have been stuck. The truck will run with the ICP unplugged but not very well. If it starts, shut it down and plug the ICP back in and try it again. If it runs, then great! if it won't run once the ICP is plugged back in, you probably need a new ICP.

There's a lot there to try, so I will let you work on that for a while and check back later today.

Good Luck!

 

your gpr SHOULD look like the one in the picture if yours is bad and needs to be replaced. that means dont go buy the cheap ones from NAPA. they work and might get you out of a bind but the one pictured is the one by white rodgers and can handle more current and lasts way longer than a stock replacement. your search term on these forums would be "Stancor Relay"

 

Thanks guys we will see how all this goes

 

Have not read a clear answer yet on this thread ... Does the WTS "wait to start light" come on when turning the key to the "ON" position?

Preferred answer is "YES" or "NO".