Hello I’m new to fords. I just bought a 99 f350 dump and ran fine when I bought it. Plowed snow for about an hour and truck died. I assumed it was fuel pump since if you sprayed starter fluid in air cleaner it would attempt to fire. So took lid pump out and put new one in and guess what still no fuel pump later to discover I have no power going to fuse for fuel pump. If I jump power from a good fuse pump runs as should but still won’t start so I’m thinking I’m missing another relay or something. Thanks in advance for any help

 

When you say "no power to fuse for fuel pump" you do mean a fuse?
There is a fuel pump relay in the relay box in the engine bay.
It is a standard relay similar to several others in the relay box which can be swapped for testing.
When you jumped power from a good fuse where did you jump it to - before or after the Inertia Cutoff switch?

 

Yes I jumped a wire from a hot fuse I think it was number 6 to fuel pump fuse I believe was number 7. So I’m assuming it’s before the inertia switch but not positive. Also I did switch all three relays around that are in the same fuse box.

 

You need to check the fuel pressure to test the pump. The fuel pump circuit has a timer on it if the engine is not running. You can test the circuit at the pump by having some one turn the key on and some else at the pump plug under the truck with a test light. I think the circuit is active for three seconds before it times out if the engine is not running, If you have very many miles on the truck more than likely its the pump not the wiring.

 

The fuel pump fuse is before the Inertia Switch, so that's all working.
Need to find a wiring diagram for your year.
With the fuel pump jumped was the pressure good at the fuel rail test port?
I think the fuel pump relay coil trigger gets power from the PCM relay.
The PCM will ground the coil trigger circuit to turn on the pump at the appropriate times.
The PCM looks at the crankshaft sensor to turn on the fuel pump, not sure if there are other inputs.
Is the PCM getting power?

 

I will check the fuel pressure next and see if the pcm is getting power it almost seems as it not but will double check will let you guys know over the weekend once I get time to work on it again thanks everyone.