2002 F-250 alternator problems!!!

[JCW]

Two new batteries and new alternator a month ago... Now the battery light in the dash flashes on and off....sometimes it stays on for 2 or 3 mins.
Does anyone know what could be the problem. Are where I can get the wiring diagram for the charging system?


thanks for your help!

[SuperCrutyPS]

What are your batteries reading while the truck is running? Down around 12V or closer to 14V?

If lower, your wire between the alternator and batts could be bad. Just a suggestion.

[NCHornet]

AutoZone Alt? The only one I would buy is the DB Electric Alternator, far better than anything you will find at any auto parts store. Also check all cables going to and from the Alt.