1999 F-250 powerstroke would not start yesterday. Got a jump and got it going. got home and the system had not charged up and would not re-start. I replaced the battery that tested "dead" and the truck cranked fine last nite and today until this evening when I returned home the amp meter showed low. Of coarse it did not crank up. Obviously it is not a battry issue. Does anyone know what this can be? I am leaning to an alternator but the fact that I can jump it off and when the cables are removed the engine does not die. I would love to here any info that you have on this.

 

Given that the powerstrokes are power hungry for electricity because of the complex engine management system, I don't think that it would run very well with a weak battery. I had a 2001 F350 7.3L that kept stalling because of one weak battery that couldn't support the power needs of the PCM. It would start and run a little bit but eventually it would die. Bout pulled all my hair out trying to figure out why it kept stalling.

 

Got little idea what started your problem, but unless Ford worked some magic, pulling the bat cables with the engine running can blow all kinds of electronics, including the alts. That test worked with generators and dinosaurs, but didn't last much longer than that! Just a thought. You don't want any sparks, which cause spike voltages, in your system.