My truck shut off on me the other day mid idle 8n my driveway. I charged the battery and watched it drain as I started truck again. I picked up two differant alternators from a pick and pull and both aren't producing power. My cables are getting power through perfectly along with power to my voltage regulator. Everything is acting normal aside from the alternator not pumping out its 14v back to the battery. There MUST be an inline fuse or a fuse somewhere for the alternator. It's an 2004 F250 5.4L gas.

 

There should be a 10 Amp fuse in the CJB (Central junction box) under the dash L/S that provides voltage to the alt field coil. (F2-45) position.
Check the junction located on the driver's side inner fender well. The output from the alt goes to that junction and then to the battery and the rest of the vehicle.
Many times if ignored, it gets corroded and doesn't allow very much current to pass.

 

Thank you very much. I moved some frelays s around under the hood and under the dash which narrowed the issue down and now all is well.

 

how many miles? I just had to replace a computer at 115,000 .

 

Hi Anthony,
What was the problem that required the computer to be replaced?
The reason I ask is because if there is something wiping out the computer , that should be checked out and corrected or it could do the same thing to the replacement computer.