2002 Ford F150 5.4 4X4 the fuel pump relay seems to be working, i hear it click using a test light but the light barely glows (my buddy suggested this might indicate a grounding out condition or something else is pulling off this relay), but no power is going to the circular 4 prong connector that connects to the fuel pump. I do not have dashes on the odometer, the theft light is not blinking, could the fuel pump driver module be the culprit, the last morning i was able to drive my truck my battery light was coming on and going off intermittently, then totally died later on the way home and has started briefly a couple of times but dies shortly after, now my battery seems to be going dead, could a low battery also cause the fuel pump not to turn on? also i have checked all fuses and the fuel pump reset in the passenger kick panel

 

Seriously, fix the dead/weak battery problem first, likely an alternator problem. Otherwise, messing with the fuel pump is like a doctor treating a broken leg first while the patient is bleeding profusely.

 

Your truck does not have a FPDM like the 04+

 

Project is right, the cart goes after the horse, not before it.

 

Try swaping the fuel pump relay with one from the trailer tow adapter ( seem to recall the battery charge relay is the same size ).

The battery issue does need to be addressed ( as noted above ) but if you are not getting the same power on both sides of the relay, this would be my suggestion.

 

If the battery is dead, the relay doesn't matter.

 

charged the battery, replaced the alternator, then jumped the fuel pump relay to pressure the line and the fuel pump did not turn on as i got no pressure and did not hear it come on, is there any way to verify if the fuel pump is bad, i have heard of wiring it straight to the battery to test it, or should i be looking somewhere else, the fuel pump is less than 4 years old. when i do jump the relay i get power to 1 out of 4 prongs on the harness that goes to the fuel pump is this correct. I have tried eight different relays

 

The 4 wires ( from the 2001 EVTM )

Pink w/ Black stripe wire = + VDC from the Fuel Inertia switch
Black = Ground

Fuel pump module ( fuel level )
Yellow w/ white stripe wire = to the instrument cluster
Black w/ Orange Stripe wire = Ground ( ref for gauge ).

If you have power to the Pink w/ Black stripe wire you know that part is functional from the fuse ( through the relay and inertia switch ) to the harness at the fuel pump.

Did you happen to use the ground on the connector when checking for VDC at the Pink w/ Black stripe wire ? ( make sure it is not a ground issue ) ?

did you try smacking the bottom of the fuel tank a few times with a rubber mallet ( don't use a hammer it can damage the tank ) ?
- Some times the fuel pump will hang up and slugging the tank will break it free. give it 8 to 10 smacks and a second before trying it.