battery gauge bouncing

[powerstrokedrivr]

hi guys. i have a 1999 f250 7.3 powerstroke, 317,000miles last night i was out doin some crusin/racing. i was beating on her pretty good. it was doing fine then i noticed my battery light came on, and my batterygauge went all the way down. headlights would dim, radio shut off, then the gauge would go back up quickly and headlights woud come back brighter and radio wouuld come back, it kept doing this. the truck never shut off, i got home, shut it off, woke up next morning. went out to start it and batterys are dead, im puzzled here, could this be the alternator?or the belt? or the tensioner? help, thanks

[Patrick Feeley]

If the belt still looks like it is inline and in good shape, you may want to check all your battery connections (all ends) to make sure they are clean and tight, have the batteries checked (independent from one another .... cables disconnected). Aftyer that maybe remove the alternator, then remove the regulator from the alt. Inspect the brushes and the copper tracks on the armature. I just replaced my alternator due to the one of the tracks being bad. Cheers!