Just bought 1999 f250 sd with 5.4l. Has no start. Checked fuel pressure (0), check fuel pump fuse- it's good, but I have no power to pin #30 on fuel pump relay. Any one have a wiring diagram so I can chase the wire?

 

Welcome to FTE.

Before you start checking the wiring, have you looked at the inertia switch?

 

The inertia switch is "downstream" from the relay, so the relay must first energize before the inertia switch factors in.

You only have about TWO SECONDS from the time the ignition switch is turned from OFF to RUN to measure fuel pump power when the engine is not running. Any measurement made outside this priming window is invalid and will cause you to get lost out in the weeds. However, pin 30, IIRC is the feed from the fuse that supplies the fuel pump circuit. Check that fuse.

 

Ya the fuse is good. And pin 30 is power from the fuse. That's why I was asking for wiring diagrams. I have pulled the fuse box apart. There is two wire attached to the pin for 30. Also have no power at the inertia switch. As far as I can find the computer pulses pin 86 to ground

 

Yes, that's the only time you can measure power at the inertia switch until the engine starts.

Do you have power at the inertia switch during THAT interval?