Engine and fuel pump wiring diagram please?

Lt blue and white/red go to pcm it may be a bad module why you loose power to inertia switch. i'm sending a pic along.try cleaning the ground for the module at left rear of car. the white red wire may not have anything only at certain times or the module Is bad. Scan it and see if anything pops up. Here are the fuel pump and engine wiring diagrams with a guide to help you test

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Please let us know what happens.

The inertia switch is supplied by the fuel pump relay it should be a dk/grn/yell wire going to switch with a pinkblk going out. That goes to a module that then powers the pump. (Pic shown of module/pump.) It cold be a bad module. Or an inertia switch that causes your power loss whe nteh fp what ever the hell connection you are talking about is plugged in. The ltblue and red both go to the pcm. One may be power and the othe maybe return to show module is activated in pcm.

Connect a jumper wire between the FPDM PWR (VPWR for Continental) pin and FP PWR pin at the FPDM harness connector.
Key on.
Measure voltage between the FP PWR circuit at the fuel pump harness connector and the battery negative post.
Is voltage greater than 10.5 volts, AND within 0.5 volt of the reading in KB72?

Yes No
KEY OFF. REMOVE jumper. VERIFY previous test steps. CHECK related connectors for corrosion, etc. If all checks are OK, REPLACE FPDM. KEY OFF. REMOVE jumper. CHECK for causes of high resistance in FP PWR circuit.

KB75 CHECK B+ TO ELECTRONIC ENGINE CONTROL (EC) POWER RELAY (CONTINENTAL), CCRM OR FPDM POWER SUPPLY RELAY
Disconnect CCRM (Escort, Mustang), electronic EC power relay (Continental) or FPDM power supply relay (all others).
Key on (to put same load on battery as previous steps).
For Escort, Mustang:
Measure voltage between pin 11 (B+) of the CCRM harness connector and the battery negative post.
For Continental:
Measure voltage between the B+ circuit at the electronic EC power relay harness connector and the battery negative post.
For all others:
Measure voltage between the B+ circuit at the FPDM power supply relay harness connector and the battery negative post.
Is voltage greater than 10.5 volts?
Yes No
KEY OFF. GO to KB76. Improper voltage is being supplied to the CCRM, FPDM power supply relay or electronic EC power relay. CHECK associated wiring, connectors, etc. REPAIR as necessary.

Try those first two steps I forgot the pic on where to put jumper it's on this reply.

Yes it does sound like a relay or fuel pump problem. Here are some guides and diagram (below) that will help you see which is the problem.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

The fuel pump has a module that why I have the test light guide

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Has a video on how to replace the pump

Please let us know what you find.

Cheers, Ken

Hello,

I have included a description of how this works from Ford in the diagrams down below. I have also included the wiring diagrams for the Engine Performance of your vehicle as well in the diagrams down below also. This guide can help you test the wiring with the engine wirindaigarms below.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.