2001 Explorer XLT fuel issue

[thunderkiss71]

I have currently ran into a roadblock trying to diagnose a fuel issue. After cutting a big ass hole in the floor to get at the pump, I still can't get power to the pump. I have replaced the relay and checked the inertia switch. I jump wired the new pump and it is working. Besides the fuse that works with the anti-theft system, I am at a complete loss what the problem could be. The car just died when my wife was delivering newspapers one night. It will fire up if I give it a spray of ether so I know thats not the problem. I also checked for pressure on the fuel rail and there isn't any confirming the pump will not run.
We have owned this since 2004 so we are the second owners. I am suspecting the inertia switch is the problem, but before I try to bypass it, I would like some helpful thoughts of what I could be missing.
Thanks in advance.

 

[TestPoint]

Do you have the electrical schematics for the truck? If so, volt meter and trace time. If not, I have the original Ford ones for the '00 which should be the same with very few deviations.

Let me and the forum know what you need.

 

[thunderkiss71]

If you have a schematic, that would be awesome to have. I need to test for power at the inertia switch to see if there is even any there. If there is, that would say can go the switch is bad w/o tripping. Like most relays, they can go bad without tripping the switch. I am trying to take one step at a time now after the misery I have been through just to get at the pump w/o dropping the tank.
Thanks again!

 

[TestPoint]

You didn't say which engine you have so here are all three.

Good luck!

 

[thunderkiss71]

It's a 2001 V6 SOHC auto. I noticed in the diagram a fuel pressure sensor. Could this be a cause of the issue of no power getting to the pump?

 

[TestPoint]

The fuel pressure sensor provides feedback to the PCM to manage the fuel pressure by pulsing the DC power to the pump. So, yes it could be a problem but not likely and not the first place I would start.

The PCM will energize the fuel pump for 2-3 seconds each time the ignition switch is turned from off to run.

I would start by measuring the voltage at the PCM side of the Inertia Cutoff Switch. If you see voltage there check at the pump side of the switch. You said you replaced the FP relay but you can pull it half out of the socket and do the electrical test there also.

Not that the switch is a common problem but I had one fail sitting at a traffic light. Reset it and got 50 miles before it kicked out again. After that never had a problem with it. Guess it was just having a bad day.