11.9v at fuel pump relay but 9.2v at inertia switch. Engine won't start

[chicknpiza2]

1995 ford explorer xlt
code 543
Engine turns over without problems but won't start. Well it was intermittently starting, but now it won't start at all.
Battery reads 11.8v and the same at the fuel pump relay, but 9.2v at inertia switch with key on engine off.
Fuses are fine.
I need help following the wires between the two points to see where the problem is.
Pictures would be heavenly but any advice would be much appreciated.

 

[410Fortune]

Your battery should be 12.4V or higher, but I am sure you know this.

fuel pump relay from 1995 is getting older, might be getting corroded internally, good idea to swap fuel pump relay with a new or known good one, at least for testing.

With 11.8V I am not surprised the truck wont start, many of the systems including the PCM and ignition require 12V+

Wiring info:

Fuel pump wiring

Anyone know how the fuel pump is wired?? Without getting into to much details on what im doing,im just looking for a schematic.. im basically trying to wire a relay to power my BIG pump and need to find a signal wire to turn the relay on.. Ive tested the relay under the hood and doesnt seem to...

www.explorerforum.com

check this out for the fuel pump wiring and low power issues

Low power to fuel pump.

I recently became the owner of a 1996 Ford Explorer XLT,4.0,auto. I did some work for said vehicle,knowing that it wouldnt start due to a fuel problem,but I figured that I would be able to repair it. Well,electrical isnt my area of expertise,and now Ime sort of stuck. heres whats happening...

www.explorerforum.com

Your 95 needs 34 PSI at the fuel rail for the engine to start.....you should:
charge battery/test/replace

Make sure all battery terminals are clean (overlooked ALL THE TIME)

Clean all ground wire location

Have a good look at the fuse and relay terminals in your power dist box, make sure its not just some corrosion

Do a fuel pressure test!