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Question: Replacing the alternator

Evolution1980

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Hey everyone...
While attempting to reconnect my battery, I think I fried my alternator's electronics. I was having a difficult time getting those damn side-terminals to connect and I was arcing pretty good. Eventually I got the connections secure, but then noticed that my battery light was full brightness without the key in the ignition.
I got the car started and the battery light went out. I wasn't getting any charging voltage (+ ~2v) at the battery. Shut the car off and removed the key, battery light came back on.

(This may be an irrelevant part of the story, but in case "details matter"...)
I restarted the car and left it idling for maybe 10-15 minutes with the hood up. Came back out and smelled something unusual and noticed a faint smoky haze. Immediately shut the car down and it proceeded to diesel like a mofo. I noticed my alternator and MSD ignition were hotter than I think they should've been. But that's just speculation that they were hotter than what would be considered normal. "Hot" being, "It probably would've burned my fingers if I had kept it on there," especially the alternator. Also, there was a lot of black residue on the bottom of the pulley side. Was it always there? I don't know. Maybe it was and I never noticed it. Or maybe that's fresh from whatever potentially went kablooey?

So I took the alternator up to an Advance Auto Parts and an O'Reilley's for a free bench test. Both of them said my alternator failed all their tests. FWIW, I didn't get the complete warm & fuzzies that either place knew exactly what they were doing with this older piece of gear. It was manufactured before they were born. (Yeah, that's a bit of a cheapshot. :SLAP)

Do I spend the time and money buying a rebuild kit and trying to rebuild it? Or just get a replacement with a limited lifetime warranty?
Here's where my thinking is thus far...(in no particular order?)
  • The alternator had the diode trio replaced maybe 15+ years ago?
  • My time is money. While I'm likely capable or performing a rebuild, I've never done it. I could spend an hour just trying to decide which place to get it from. Then the rest of the day watching YouTube videos that walk me through replacing the parts.
  • The rebuild kit (say $40'ish?) + my time (at least 2 hours when I'm realistic about it) --vs-- just buying a plug & play replacement? Advance Auto has the AC Delco for like $75. A different brand reman for like $65. I'm not even certain that a rebuild kit will resolve whatever problem I have.
    • I guess that same logic applies to replacing the entire alternator...there may still be an underlying issue such as some bad wiring.
  • I'm leaning towards purchasing the AC Delco unit so I can just drop it in and hopefully be back in business.
So what does the peanut gallery say? If you're on the "just buy a new one" train, any recommendations on brand and/or place to buy it?
 

bill81vette

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Hey!Andre how have you been? I have rebuilt mine.Eg,new brushes and diode trio.I used toothpicks to hold the brushes back uncheaper and til I reassembled the case.I thought it was much less expensive than a reman,plus its the alt.that it was built with.not to mention the satisfaction of doing it my self!
 

gmjunkie

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Hey Evo,Shit Happens when your having fun! LoL! I think a man of your caliber can rebuild it standing on your head! Be sure to check the bigger diodes too and windings while you have it apart besides changing the trio ,Sometimes one of them can be the problem and slipping AC voltage to other components and make them over heat. The bigger ones shorted will definitely turn the light on Bright with the key off.
 

Tom Bryant

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Hi Andre,
With your positive cable connected first and tightened I can't imagine that the amount of arcing from the ground terminal while connecting would cause any problem. A certain amount of sparks is part of the game with those side terminals. If you decide to disassemble I can run you through the testing of the individual components if you don't have a manual.

Tom
 
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Evolution1980

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OK, Y'all convinced me to give the rebuild a shot! :beer
Suggestions on where to buy the rebuild kit? (A direct link to what I need would be nice!)
 

Tom Bryant

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I'd disassemble and check the components separately so as to not waste money buying what you don't need.
 
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Evolution1980

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I'd disassemble and check the components separately so as to not waste money buying what you don't need.
At this point, my time is more valuable than what I'd spend testing individual pieces. As I understand it, the rebuild kits come with "everything", so I'll replace "everything". I'm not going to tear into it to replace only the diode trio and not the brushes or whatever else is in the kit.
Unless I'm not understanding your comment.

Any recommendations on where to acquire the rebuild kits? I.e., "Where would you buy a rebuild kit for yourself?"
Anything in particular I need to know to ensure I get the proper kit?
 

Tom Bryant

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I'm just cheap. Back when reparsing these was common in the dealer shop, rectifier bridges and diode trios were the common things to die with the rectifier making the most smoke. We almost always replaced the brush and holder assembly too unless they looked new. I'd do the front and rear bearings just because it's apart and if the brush surface on the rotor is good I'd test it and reuse if tests good. Same for the stator. If either of those is fried it should be pretty obvious when it's apart.

Tom
 
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Evolution1980

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This is the only rebuild kit I've been able to find online, and it's not available for two weeks.

Anyone have other references where I can buy the rebuild kit?
Otherwise, I'll just pop for a whole new unit. Example
 

Tom Bryant

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That's a good price for a rebuilt and It's AC/Delco. Only giving $7.00 back for a core charge so I'd keep the original. Get the kit and rebuild it at your leisure for a backup.
 
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Evolution1980

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$37 for a rebuild kit plus time and effort versus $45 for one already rebuilt. Seems like a no brainer to me.
Yeah. Since Summit Racing is only 30 minutes from me, I just went up there today and picked up the reman.
Even though it was a 10si (I guess that's a form-factor designation?), it was pretty much a direct swap.
The bolts were a little smaller with this unit and the wings(?) for mounting it were a bit shorter. But nothing that a little adjustment of my mounting arms couldn't account for. And the plug was on more on top instead of on the bottom. Fortunately, there was just enough wire for it to reach.

And now we be back in bidness!!! I actually plan on driving it this year! Gonna be putting the 'driving' insurance back on it tomorrow.
 

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