I had an alternator fail and I replaced it. Started the truck up and started driving and managed to make it a few miles down the road before voltage dropped and truck quit. I pulled the new alternator off and the battery and had them both tested. Tested OK. I charged the battery and tried again. Alternator wasn't putting any voltage out this time. I took the alternator in again to have it checked and it checked OK. They replaced it as I insisted there was no voltage other than battery volts. I installed the alternator and no change. The battery light on the dash is on dim and there is no voltage coming from the alternator other than battery voltage. I've checked the fuses for the alternator regulator and they check fine. Am I missing something simple? What else should I look at?

 

Did you check the big fuse [fuseable link /175 amp I think] behind the plastic cover on the firewall passenger side?

 

I found and checked one fuseable link between the alternator and the starter solenoid. It checks good. I did not find another one under a plastic cover on the R/H side. I also did one more check by disconnecting the battery while running (not a good idea I know but) and it died immediately. Does anyone have a copy of the wiring diagram of the charging system for a 2001 F-250 4x4 5.4L?
Thanks

 

Try here: http://www.ahdol.com/

 

Well it's off to the Ford Dealer tomorrow. Apparently my truck does not fit the standard wiring diagram as I purchased a manual today and I do not have the fuses located next to the battery. Still no charging from the alternator and I've done all I can do. I'll post what Ford finds.

 

I'm having a similar problem with my 2000 F-150. What did Ford find?

 

Uh oh. Today on my way home from picking up the kids the battery light came on. I did not have far to go to get home. I pulled into the garage, shut her off, restarted and the light went away.

I am wondering if I should just make an appointment right now, or if I should wait it out and see if it happens again.

2008, brand new, less than 3000 miles on her.

 

did you find the problem? i have a similar issue.