Why Amy I getting 6v and not 12v at my fuel pump. I have replaced the pump and relay

Are you getting the ignition activated voltage to the relay? If you are, and you can jump across the relay to turn on the pump, I would say your relay is defective. If you know the relay pins for the ignition input and ground, you should be able to test it outside its plug in socket. You should hear it click when +12V and ground are applied to the proper pins/connectors for the ignition voltage. An ohm meter could be put across the supply +12V and fuel pump pins/connectors to really check the operation. If you think your relay is good. I would start checking for a bad +12V connection for your ignition supply, as well as the +12V that is switched through the relay. And the grounds to all. Use some contact cleaner on relay pins and socket. Ignition switch contacts can cause issues too. If it stays broke at least it should be easier to find than something that is intermittent. Based on what you stated, most of your troubleshooting should be at the relay socket (knowing which connectors do what) to isolate the issue to the relay, your ignition voltage, or your fuel pump voltage. After that it is knowing which step to take next.

All cars, EFI. (some have 3 fuse to operate ECU/spark/ fuel) check em yet?
check power to pump 12v cranking?
no, ? 12v, or 6v? (6v or near is corroded wires /conns)
check power (12v) from fuel pump relay cranking, got 12v there.
if yes , the the path is broken to the rear ) (inertial switch?, not in 95)
if not,12v now, the FP relay is bad or ECU is not turning it on.
if 12v is across the FP relay coil the ECU is working.
if 12v is across this relay, and output is dead, that is a bad relay
or the FI use feeding it is blown.
btw #1 all cars cut fuel (INJ) when spark is detected bad. (ecu)
btw#2 some (software) cut the fuel pump for same reasons.
btw#3, most cars, only activate the FP relay for 3 seconds key on, each time. and some cars only cranking, and running.
all these facts, need to be known to make progress, in EFI.
and more.

The relay should have been trouble shot BEFORE changing out the pump. If you've got 12v at the pump it is not the pump. Unless you installed a bad pump. But, no 12v at the pump= bad relay. But ten you've got to see what activates the fuel pump relay.

With my pump failure, I read the exact same 6.5 v at the inertia switch in my trunk with the key in the "on" position and engine not running or cranking. When cranking, the voltage to the pump jumped to +12V and if the engine did run, the voltage should stay at +12V.

The Ford manual states +12v should be at the motor for some number of seconds in the key "on" position then drop off if the engine is not cranking or does not start. In my pump failure case, I never saw 12V at the inertia switch in just the key "on" position, only +6.5V as the +12v fuel relay under the hood never engaged and/or stayed latched on.

In my situation, I measured an open circuit at the pump motor winding and suspect the +6.5V I was reading came from the Powertrain Control Module. I am also guessing if my pump winding was not open, the +6v voltage would have been +12v for a number of seconds for fuel priming as the fuel pump relay is temporarily energized, then drop to zero (relay off) if the engine does not continue to crank or run.

With my pump motor winding open, the Power Control Module may not have been loaded properly to function (reading +6.5 floating volts instead) in the key "on" position and therefore never climbed to the full +12V. There obviously was no fuel pressure at my schrader valve on the fuel rail when cranking which indicated an open wiring circuit (splice, ground or connector) or open pump winding. The 12v I was reading when cranking at least indicated the fuel pump relay was working.

With my new pump installed, I listened for the pump running in just the key "on" position. I believe I barely heard it running after the repair as it was running very quietly which indicates the +12v was there which supports my theory.

You need to cuss a whole lot more than twice. A voltage meter would be more useful in determining the actual voltage making it to the fuel pump. Something around 12v DC would be appropriate. If you are not getting at least 12v, you need to check the battery, the starter relay, and the fuses to the fuel pump for any corrosion, and make sure you are getting at or near 12v DC.

check all those item again, especially the crank sensor, check the fuel pump by adding 12v to it, make sure its good. tun on key, make sure your getting 12v from fuel pump wire

ignition module

first step check fuel pump relay for 12v.If 12v is there check for ground on the coil side.if there is a good ground plug relay back in and see if there is 12v on the side of fuel pump.if there is under 12v the relay is bad if it does have 12v u have a bad wire to the fuel pump.

I would check the ground for the fuel pump relay that operates the switch side of the relay.
You should have 2 12v inputs to the relay. When the relay gets 12v input, it closes the relay switch on the heavy current side that sends 12v to the fuel pump.

A relay is needed because you don't want heavy current going through the switch.

Also, most cars only run the fuel pump for 2 seconds when the key is turned on because you don't want the fuel pump running without the car running. If you listen closely at the fuel tank, you should hear the pump run for 2 seconds when you turn the key to "ON"
When the key is turned to "START", the fuel pump should run continuously.
The engine computer tells the fuel pump to shut off if the engine rpms are zero.
So, I would check the switch side of the relay. Power amd ground.

Look for the fuel pump relay and replace it.


Robert