04 F-150 Fuel Pump Issues

Juan_Hong_Loe · Jul 29, 2009

Working on Lewis' 04 Ford F-150. The engine is cranking over but not starting, doesn't even act like it wants to start. Does anyone have any access to the wiring schematics for the pump/sending unit so I can make sure there is power where there is supposed to be power? Here is what I got in my searching so far. On the plug that goes to the pump/sending unit there is 4 wires, Red/Black (which has 12 volt with key on), Black/White (12 Volts with key on), Yellow/white (not getting anything), Black/orange (Nothing here either). If I'm thinking right I have voltage going to the pump but it's bad. Just want to double check though. Thanks!

rocfun · Jul 29, 2009

i had an '04 and had to have mine replaced, but mine was running like crap. at the dealership they said the '04's fuel pumps were bad about going out. but they are not fun to put in thats for sure, especially with a full tank (ask me how i know)

Juan_Hong_Loe · Jul 29, 2009

This one should not be hard since its in a custom fuel cell on the back. Here's what i found out. Red/back wire should be hot, brown/white wire controls the pulse width modulation. Well I decided to unhook the plug from the unit and hook a direct 12 volts to it and nothing happened. So that leads me to believe that the pump is bad. But why am I getting a positive feed from both of the wires? Maybe the fuel pump module is bad? Guess I'll call the dealership and talk to the service guys tomorrow and see if they can tell me where it is and what wires should be doing what. :dunno: