no click no crank. I’ve replaced the starter, neutral safety switch and cylinder, both 40 relays and starter relay in engine compartment, and 5amp fuse in the can. Truck starts off i jump the relay slot but not with the key

 

Welcome to the forum

Assuming no Flashing "Lock" light on dash with key on, the flashing light means START is disabled, PATS(passive anti-theft system) issue

Try shifting transmission to Neutral, and then turn key to START, assuming automatic trans, if engine cranks then Neutral switch is out of adjustment or shifter cable is

Fuse 21 in cab fuse box is where to "start", pun intended

Wiring diagram below

You will see in the diagram that when key(ignition switch) is Turned to START 12volts is sent to fuse 21(just in START, not key ON)
Pull out fuse 21 and use a volt meter/test light to see if there is 12volts on one of the fuse contacts with key in START position
If so then wire from ignition switch to fuse 21 is OK, skip to next test

If no 12v then that's the problem, you could jump 12v to one of fuse 21's contacts(try both, one is IN and one is OUT), fuse out, to see if starter activates(key has to be on, no flashing light)

If fuse 21 has 12v in START then put fuse back in

Go to engine bay fuse box
Pull out starter relay
Test slots with volt meter/test light

Ford used two different types of relays, mini and micro
Mini seen here: https://www.gtsparkplugs.com/images/...iring-840x.jpg
Micro seen here: https://www.gtsparkplugs.com/images/...lay-wiring.jpg

This applies to both types
Slots 30 and 87, one will have 12volts all the time, from fuse 7 in engine bay, the other goes to starter motor
85 and 86, one is a ground, with key on only, the other is the 12volts from fuse 21 that passes thru the Neutral switch
You can use volt meter test light to determine which is the ground, key on so the other one will need to be 12v when key is turned to START

 

I'm having a similar issue but mine is more intermittent and has something to do with my pcm as well yesterday after it rained and I charged my battery my pcm was able to communicate with my scan tool when previously it wasn’t able to. so I figured it was probably a bad battery especially since I got a bunch of low voltage codes in other modules so I swapped battery for a new one and also have checked my grounds. And I replaced my battery terminals. It seems very odd when the pcm is not communicating pats light flashes like key off when the keys on. In other words there is no difference. Anyway after I replaced battery and terminals I still got low voltage reedings in my modules. I also tried replacing my neutral safety switch but I don’t believe that has anything to do with the pcm communication.

 

Also forgot to mention I checked my fuses and relays as well I also tested all my pcm pins both power and grounds with test light and they all checked out so I’m thinking to replace my power and ground pins by my pcm but I’m getting very frustrated at this point