DIY Alternator Rebuild?

[InfiniteGSX]

Ok, I just got a used alternator from a friend. I brought it to vatozone and it checked out with flying colors. I tested my voltage with the car off at 12.6. Couple days prior I tested the voltage and it was 12.6 also.... so battery is good. Started the car and tested, and it was 13.6. This was a week ago...... Everything has been fine, till today... I drove 30 miles to get fuel and came home. Then I went to go do a small photo shooot with the talon and started noticing my car was having trouble starting each time I moved it and took a shot. So I went to another location and then my stereo started freaking out. So I pulled over and checked the battery, 8.7volts!!!!! WTF, why would an alternator just quit like that?

Anyway, Saw on Vfaq about how to rebuild the alternator. I've already taken apart a few, so it looks easy as hell. I've done motor builds and other crap like this so it shouldn't be rough.

But I wanted to get opinions from people thats done it before.

 

[Mr PopUps]

Cheap enough to get a new alt. Get the Canadian one if you can, its 90amps, not 75.

 

[DSM1G90]

But, get a "real" alternator at NAPA, don't go to 'AUTOCRAPZONE' for one of their rebuilts, for you'll be seeing them quite frequently.

I've done my ALT rebuilds before, but with older ones. Just have to make sure that the brushes seat fully and the COM isn't burnished or pitted, otherwise it'll have to be turned smooth, the regulator connections are tight and bearings are new.

DSM

 

[InfiniteGSX]

Yeah, Uhm. If I woulda thought of that I wouldn't have made this post. No seriously, I did think of that. but I would rather pay 0... or in this case. 10 bucks for the new Brushes and rebuild it myself and get the satisfaction that I "DID IT MYSELF". Hense the DIY.

 

[Mr PopUps]

Yeah, Uhm. If I woulda thought of that I wouldn't have made this post. No seriously, I did think of that. but I would rather pay 0... or in this case. 10 bucks for the new Brushes and rebuild it myself and get the satisfaction that I "DID IT MYSELF". Hense the DIY.

Well i certainly didnt think id get a big fat tude for my suggestion. The reason the alt's fail in the first place is PS fluid. Good luck getting that out all the way. I mean its your car, do what you want, but dont ask for advice and then cop a tude when someone says something you dont like.

 

[InfiniteGSX]

I wasn't giving you attitude, and didn't mean for it to come off that way. My Bad. No, there is no power steering fluid. Thats how my last one died. This one hasn't ever been touched by it. I removed the Power Steering a few weeks ago. Right when I got the alternator that is... The alternator is clean. It doesn't look to be used much at all. There is no oil, grease, nothing on it. Which is why I'm confused as to why it died.

If I had the money, I'd do it. Plus I wanna learn. I'm broke. I just had to buy a stock turbo to replace my e3b16g that was smoking like a chimney. Then I had tons of oil leaks and other crap. So I just can't afford it right now. And I read the thing on vfaq and found out that the brushes are only a few bucks each. I've already pulled apart two alternators so I know how the internals are, And looks to be easy as hell. But wanted to see what people that have done it, have to say. Yesterday this alternator was charging fine, today it isn't.

 

[snowborder714]

If you don't have a heat shield, that could be a contributing factor in alternator death.

 

[My1GLaser]

I have "upgraded" to a Saturn alternator and rebuilt that, but not the Mistu one.

I got a 150 amp stator, HD voltage regulator, brushes, and shaft bearings for a total of $70 from the local alternator shop. (The stator was $50)

Took me about 2 hrs. I had to take it to them fully disassembled to have them unsoldered/resoldered the new stator in for me. My soldering iron would not get hot enough to melt the solder on those huge Stator windings.

I have had it on for probably about 4000 miles/9 months with no issues.

 

[Cesar]

it may not be your alternator.

i worked in an alt rebuild shop. mostly disassembly. not that complicated.

but if you never done it before, do your homework.

 

[Bud92gsx]

Ok josh first of all you have checked ALL the wires from battery to starter? The charge back wires from alt to batt?

Also like brian said, if theres no heat sheild then that will cause early alt failures as well..

Now talking about t the alternator...You have taken the one apart on your car? I know you said you took apart others, but the one your using is the one I want to discuss.. It might just be the brushes on the inside, that's an easy fix..Make sure you look at the windings and make sure nothings wrong and there connected and such..

 

[InfiniteGSX]

I've taken apart my old one that died most likely to ps fluid leak. And a 420A Alternator.

I have tested the charge wire with the car on, charge wire connecting to the alternator has the same voltage the battery does. All the way up to the 80amp fuse, both sides have current going through them so the amp is good. So that leads me to believe the alternator is not putting out any voltage at all. I dunno if there is a relay that switches the alternator on? or no? Cause if there is I haven't checked that yet.

Saturn Alternator?

Also if you go with a higher amperage alternator, do you gotta upgrade the alternator fuse from the 80 amp it is stock to something higher? I'd love to have something better. I'm gonna check this alternator to see if its an autozone one or a Mitsu one. Cause its very clean if its an oem. I think it has to be a year old.

 

[My1GLaser]

There is a thread in the DSMLink forums about changing to the Saturn alternator, which is better at lower rpms and holds better voltage at WOT. Its not a direct swap, but it was a fairly straightforward modification. You have to grind some on the Saturn alt, the ear on the block, flip the adj bracket over, find a saturn pigtail and run a new 12v signal wire. There might be a thread on tuners somewhere.

You can probably get an upgraded stator for your mitsu alt. I have the same 80 amp fuse, since I don't draw more current than before the mod. Its just better when there is more power demand on it. I did upgrade to a 4ga wire from the alt to batt. I also added 3 or 4 more 4ga ground wires around the engine bay to help the charging system.

 

[Mr PopUps]

Oh duh, the most obvious thing would be to check the main fuseable link. Its the black one that sits at an angle to the rest. Its normally only 80amp, but you can get a 100amp and put it in. Like i said, you may have to ask for the CA one.
Like ive said in other posts, ive been gone from DSM's for 7 years . Kinda funny how much stuff is coming back.

No biggie on the tude thing though

 

[InfiniteGSX]

No, fuse is fine. that was the first thing I checked. I checked both ends for continuity and for voltage. I found the Alternator relay. Started the car, unplugged it and it was only two wires connected to the relay. I put a volt meter on the car while it was running, voltage didn't change and I plugged the two wires together, and the voltage jumped up to 13.0 and started to climb. Then it dropped, and then rose again. Seems like the alternator is working but something might be dirty?

The saturn alternator thing I might wanna check out. Cause I'll most likely be going with a used alternator...

 

[93ETGOCART]

just try the new brushes its cheap enough anyways

 

[InfiniteGSX]

Thats what I'm thinking. either they are dirty or just worn out enough that it doesn't make conductivity anymore.

 

[93ETGOCART]

yeah my moms went out like a week ago and me and dad messed around with the brushes and put it back on the car and it worked for about another day so im sure a new brush would of done the trick but it wasnt my car so i wouldnt of done it. but if it was the talon and thats all that was wrong with it you best believe id spend the 10 before i spent the 90 on a new alternator

 

[InfiniteGSX]

Ok. strange... I had the car on the charger so the battery is fully charged. I need to move my other project, that doesn't start right yet... So I back the talon up to it, to pull it to a different spot. felt like testing the alternator again. I hookup the volt meter to the charge port and to ground, 12.3. So I tap the alternator with a small metal bar, and the volts jump to 13.8-14. Where it should be.

I set my RPM's with the car running right, to 850. Lately when the alternator isn't working, my rpm's are around 1100ish. when the volts jumped to where they should be, my rpm's drop back down to 850 where I have it set. What do you guys think? bad ground? Bad connection on the inside? Dirt?

 

[93ETGOCART]

sounds like somethin is loose in the alternator or the brushes are just getting stuck

 

[InfiniteGSX]

Yeah... everytime the RPM's rise again, I look at the volt meter and the volts drop back down... Then I tap the alternator and rpm's drop and the volts are back up. hahaha.

If I take the alternator apart, I'm just worried about not getting the brushes to resess themselves so I can put the center back on.

 

[93ETGOCART]

yep but its either chance it or go buy a new one

 

[InfiniteGSX]

One way or the other I gotta try. cause to pay to have this one rebuilt costs about the same as buying a new one with lifetime warranty. So I can try to rebuild this one, and if I fail... I fail.

 

[93ETGOCART]

and if you can do it you get cheap alternator rebuilds forever.

 

[InfiniteGSX]

I don't think I'll have any issues. Just gotta stay away from that skinny razor that separates the bottom bearing with the piece that rubs up against the brushes... I was trying to take the bearing off and wanted to wipe it clean and cut a huge gash open in my hand.

 

[93ETGOCART]

bummer i was hacking part of my car off today and caught a metal shaving in the eye. go figure my safety glasses were on top of my head at the time