I realy dont expect anyone to have an answer to my problem but at a loss for answers. I am helping a friend with his 2004 f150 5.4. His truck quit him and found it to be a faulty fuel pump.
We removed the bed and removed pump. He bought a new complete assembly the next day.
I had him check the fpdm and it was all corroded as I suspected even had a hole in the back. He patched it up. When we hooked the pump up and tried it. The pcm went crazy.The theft light blinked rapidly, the starter wouldnt engage, the elec throttle was making noise, and the fuel pump clicked at the speed of theft light. The scanner would not comunicate with pcm. I unpluged the fpdm and the pcm went back normal. So we repaced the fpdm with new one and that made no diff. I left fpdm pluged and unplugged the fuel pump and went back to normal. I could talk to pcm with scan tool and no codes. Live data looks normal in KOEO .As soon as I plug the pump in all goes crazy. I plugged the old pump that was bad and it acted the same way. It got late and didnt get to check pcm power and grounds but when you unplug fuel pump pcm acts normal. The pcm and FPDM have a bus connection but the pump does not have a feedback to pcm.

 

I joined this site hoping to get help or maybe some ideas.I thought maybe I could help others.

Of course I had to figure it out
myself. In case anyone else runs into this problem here was my fix.
First I checked my fuses. They all
checked fine with test light. After
studying schematic I realized fuse
34 of CJB could have feedback power on both sides of fuse. So I
removed the fuse and it was blown. I replaced it and
all fixed.I dont I don't mean to be bragging, but I have been a Ford
tech since the 1974. I am now retiered. A senior Master
from 2000 to 2010. ASE master tech in car and truck.
and both advance courses auto and diesel. Got a 25 year medallion from ASE. Gold certifed through Chysler.
I do appreciate responce from Jahne B.