hi, i no longer have this truck but asked for help from the second owner after its sale.
while going up hill and running real well, the engine cut out and was unable to start again.
ignition tester used and found no spark.
fuel pump will only run if hot wired.
found no blown fuses ?
any one any idea, thanks in advance, thanks bokker.

 

Any chance it is a bad ignition switch?

(good to see your name again bokker. Hope you are doing well)

 

hi, thanks for that, it nice to know. i am better for not having to crawling in and around this truck.
i will pass on your information as it sounds like a fair chance of being correct.
thanks again bokker.

 

I thought more about my idea, and started to second guessed it. I assume the dash powers up, etc. so that makes me think the switch itself is likely ok.

But.... the symptoms do seem to match what you would expect if the ignition switch signal was missing somewhere down the line.
If the starter spins, but no fuel pump and no spark, I would sure be checking the wiring harness and signals.
I have limited knowledge in this area and would have to resort to a shop manual or good service manual to trace down the wiring.

AH! Just had another idea! The inertia safety cutoff relay. If it trips it does what you describe.
THAT sounds like it might be the problem. I believe all the F150 relays are behind the kick panel on the right side of the passenger's floor.

 

hi, that switch is very lightly the cause, sounds good. my friends dodge ram failed and also locked the seat belts back so i should have guessed. thanks for your help. will post if it is the cure. bokker.

 

also if it is the inertia switch it says so. on your gauges it will light up "fuel system" or something like that...

 

hi, i have just had info back from the owner, it turns out it was a computer fault and it just shut-down ! all sorted now.
thanks for the help, bokker.