I have A 1988 Ford F-250 4x4 i got it home and it died and it will crank but not run. i can put some starter fluid in it and it starts right up. so i figured its the fuel pump. and i figured the 2 pumps in the tank wouldn't go bad so i changed the fuel pump in line and also the fuel filter and it still doesn't start. i tested power on the fuel pump and theres no power. i looked at the enirtia switch and its good. I replaced the relay also so thats good. idk where to go from here. and need help. thank you.

 

welcome to FTE.
first thing to do is check for power coming out of the relay. then power into the relay.
fuel pump power is sent to the relay through the engine computer.

 

When testing for power to the fuel pump(s) check it at the Inertia switch with a loading test light.

Note you will only have power at the Inertia switch for one second each time the key is turned on.

If you do not have power at the Inertia switch for one second then check the bottom of the two relays for a bad wire.


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Can run the fuel pump self test while diagnosing, so as not to rely on the 1 sec key prime.