Relatively New Alternator Went Bad Any Ideas

[frank]

I took my 69RR w/383 on a 4 hour drive (one way); about 3 hours the gages went crazy tacking back and forth, than settled down I was running between 65 & 70. On the way home the lights, gages and all electrical slowly died, seems that the last couple of hours the car ran off the battery, at that point I knew the alternator was done. I’m going to have it tested but I’m sure it’s done for. Any ideas what might have happened ????

Frank

 

[super-bee_ski]

Could be the rectifer (Diodes) in the alternator.
If its the Alternator.

Could also be a bad ground but seemingly, the alternator.

Did you check your battery w/ a multimeter to see if it has lost it's voltage?
(Another sign alternator is not charging battery)

Yeah, first things first:
1. Pull alternator and take it in for a bench test.

 

[Meep-Meep]

As above but also check the regulator. Full fielding the alternator would be a good step.

 

[greenmachine]

Had the same thing happen when I lost the stater in my alt. make sure battery is fully charged before wiring up new alt. or else it will strain new alt. and fry it trying to run electrical system and charge battery simultaneously.

 

[Bruzilla]

I think Meep Meep got it right. Your gauges going wild was likely your voltage regulator dying, and there's a good chance something in your alternator got cooked. I had the same thing happen to me on a 73 Road Runner. The overload from the regulator dying was so strong it not only killed the alternator but blew a digital clock on the dash out of its mount and into the back seat.

 

[moparcanuck]

I've had 4 NAPA alternators go on me in as many years. Chinese crap. I found a place that rebuilds them using quality parts and have had no problems since.

 

[1962savoy]

Been there done that!!! had a brand new denso go bad puked out the regulators twice and then finally it arked the computator and finished it. just chinese crap I guess?
biggest waste of $130 smackers!

 

[frank]

Thanks everyone for your input

Any suggestion on where I can get a GOOD voltage regulator?

Frank

 

[scotts74birds]

No advice on voltage regulators. But unless the alternator is squealing, or smells like burned electrics, or bearings are bad, the problem is usually the "rectifier". All modern alternators are actually 3-phase, AC generators. This is done because it is easier, and lighter to make an AC generator, and transform it to DC, than build and run a DC generator. The "rectifier" is usually a "bolt-on" unit on the back of the alternator. These average about $12 bucks. Look it up on WIKI to see how it works.

 

[A383Wing]

the gauges going crazy back & forth sounds like the instrument cluster regulator is going bad...replace that as well

 

[ilm65]

the gauges going crazy back & forth sounds like the instrument cluster regulator is going bad...replace that as well

I agree with A383Wing--and when you do, go with the new solid state instrument voltage regulator--they're twice the price, but you'll never have to replace it again--and it'll protect your gauges forever. Got mine at rosevillemoparts.com --$60, but total piece of mind!

 

[frank]

ilm65

Thanks for the info, I truly don't mind paying that price for piece of mind.