2004 F-250, 5.4l gas. Won't start or even crank.

If you mean the car won`t turn over then you could have a bad starter motor/solenoid. check voltage at the large wire terminal on the starter it should be battery voltage. then check voltage on the smaller wire terminal it should be battery voltage only when cranking. if not you will have to check out the wires for lose of voltage. make sure the starter has a good ground. if these are good then you have a bad starter that needs replacing.

no cranks, (A/T or M/T?)(
battery lugs cleaned?
Key turned on , CEL glows in dash, Check engine light>? yes, good.
does car crank jumper cable started.??????
if yes, your battery is bad or discharged, (good batteries can just be discharged, discharged dont make them bad, only dead or weak)
if ,jumper fails, to crank it fast.
then hot wire the solenoid (on side of starter caseing)
key in pocket, '
jump the big lug to the very tiny lug on the solenoid
cranks , not? bad starter
yes cranks but dont run, good, key is in pocket for safety, this is normal
but the KEY line is dead.
bad PRNDL switch
see the tricks section here

http://www.fixkick.com/nocrank.html#tricks

Do you have power at the starter terminals ?
Could be something between the starter and the key switch such as the neutral safety switch.

With a voltage meter see how many volts are at the starter terminal. If not 12+ volts you have a bad connection. Check connection at the starter solenoid. Does it have 12+volts? Short the solenoid. Does it put voltage to the starter?

no crank!, if it cant crank, it can never start.
can be many thing.
1: dead battery or dirty terminals.
2: discharged battery (charge it or try test known good battery)
3: bad starter system.
Every way, possible , is here
http://www.fixkick.com/nocrank.html

Check to make sure you are getting voltage to the small post on the starter solenoid when the key is turned to the "crank" position. if so, check all of you connections on the battery cables. If your connections are all good, your cables are in good shape, and you still do not get the starter to crank, I would have the starter removed and tested.

check all wires to starter motor for bad earth.....make sure power reaching starter motor.....check starter motor isnt stuck

Try this procedure:
Check the battery like this:
Turn on the headlights, then try to start the car.
If the headlights do not dim or go out, then the battery is likely ok.
Check that the battery cable plus post, goes to the starter, Minus post to a good ground, like the engine.
If wiring is ok, then look at the starter solenoid for a good connection, and proper voltage at the starter.
Problem is most likely the Solenoid's bendix gear or starting relay, Have someone bang on the starter while you try to start the car. This usually works by dislodging the bendix gear..
Hope this helps.

sorry turns over means ZERO
the crank shaft can spin or not
the starter can in fact spin and crankshaft not.
and some think turns over means, engine runs. now that fact makes turns over, a dead statement.

the word is cranks over, the engine cranks over robustlyl
and then the engine runs.
then runs for more that 3 seconds, and the ASD relay holds. (step by step his works like this ,93 to now)

wont crank ? (clear statement in fact)
cranks ok, (crank shaft spins fast) can be seen and heard.
runs for 3 seconds? and stalls (ASD relay drop out) can be seen.
runs for 5min and stalls. (complex)
runs for hours and stalls. (even more complex)
all are key facts to the solution.

tell more..... tell all it does good bad or ugly
for better suggestions!

check ur starter if the car does not crank then thats what it is.