Alternator question...

[Blade]

Hey guys,

Been away for awhile, things on the sight have sure changed.  Anyway, back to business.  I've got a two field alternator in the '68 R/T that I think is going bad.  When I started it last week (first time since January) the alternator belt start squeeling like a pig.  I checked the belt and it was tight, but I played around with the adjustment anyway, just to be sure.  I start it up again, and still the squeeling when revved to 1500-2000 rpm.  Also, the alternator gauge is almost pegged to the charge side when idling. Are the bearings in the alternator going bad, not letting the pulley spin freely and causing the belt to skip a little?  Your thoughts please.  Thanks

[owatajrkiam]

Change the alt,it is fried.The same thing happened to mine.First thing that happens is you're headlights blow from the heavy voltage when revved up.I think this is common to a lot of the older mopar alts.Glen

[Nacho-RT74]

You can have several fails there at the same time, and probably starting for the same reason... bearings.

Release the allt tension and try to spin it with hand. Damaged bearing are able to feel  and hear it spinning it with hand. Alt must spin completely free, without any kind of sound or vibration. In fact alt should be keeping spinning when you give it some push.

You can check also for anykind of axial movement.

Sometimes is not really both of the  bearings as the front alt housing what it could be worn because to much alt belt tension, and that could cause out of center rotor damaging rear bearing at the same time, what makes rotor contacts oftenly the stator, and brushes out of place.

That movement also causes brushes isolators broke and then go to ground, what makes a constant high output juice or maybe high voltage output, but poor amperage charge.

An alt is an easy piece to rebuilt if you have an extractor.

[Blade]

Just tried to spin it freely with the belt off, it maybe goes 1 1/2 turns after I let go...maybe.  I will be picking up a new Alt shortly.  Thanks for the help!