

If you are testing and the truck has not started, the PCM will shut off the Fuel pump after 5 seconds ( 8 ? ) of not having started. The fuel pump relay coil is powered by the PCM power relay. The fuel pump relay normally open contact is powered by Fuse #34 ( this fuse also feeds the PCM ).

The PCM is also connected to the fuel pump driver module The fuel pump is powered from the Fuel pump relay ( non serviceable in the Cab fuse panel ) to the fuel inertia switch to the fuel pump driver module. If it is a New body style, have you checked / replaced the fuel pump driver module ? This is on the cross member by the spare tire, and some times they get corroded and crack. Is this a 2004 New Body style or 2004 Heritage / Lightning ?

Have you checked the fuel inertia switch in the passenger side kick panel ? Not sure what secondary fuel mod you are posting about, can you explain what this is ?
