Bfenty

Well, I think I might have to eat some humble pie. Against the advice of several forum members on this thread, I painted my alternator. I thought I was careful, but I went for an hour drive yesterday and it was pretty hot outside. On my way home, voltage started dropping pretty substantially. I parked and lifted the hood, and the wire in the picture was sparking against the alternator. It was doing that with the car completely off. I don't think this wire is supposed to go to ground when the car isn't running, which means I've probably got a short, right? The post is also loose and wiggling, and there's some black rubbery stuff around it that's melted. There was a rubber hood over the wire, not sure if that's where the melted rubber comes from or if it's from inside the alternator.

Now the question-this sounds like the alternator is burned out, right? Or is there something else I'm missing? Thank you, and sorry to anyone I doubted about painting the alternator.

EDIT: In pic the rubber hood is not on the wire. It was on and I took off for picture.




This wire was loose and arcing every time I touched it pretty substantially. I was concerned it would start a fire.

Joe C

hard to tell anything from your pic, but the 12V output wire should be isolated from the case - the isolator assembly looks something like this...


to be on the safe side, and without a full diagnostic, i'd say, you're looking at a rebuild or replacement.

WVZR-1

I'd think the failure is "self-inflicted" because of the removal to paint and NOT the painting operation. You very likely tweaked the positive post when you removed or perhaps when you reinstalled. 17SI parts should be available locally I'd think and maybe you just have a shop do it. It's a very easy build so a DIY is also an option. You save nothing other than maybe the stator & rotor internally, they need checked by a shop. Housings, fan and pulley likely survived but with your arching etc maybe the stator housing didn't and needs checked. The drive-end I'd think fine.

A DIY? If you think maybe - here's a link to potential parts required.

http://store.alternatorparts.com/17si.aspx

bjankuski

You shorted the power wire to the case, move the wire away from the case and see if the alternator will charge. I doubt the painting of the alternator had anything to do with the current issue you are having.

JimLentz

I've got to wonder if that paint might be conductive, most aren't. You could check with an ohmmeter.

Bfenty

Thanks for all the replies. Went to have it tested, looks like there was a blown diode in the alternator. And yes, it DEFINITELY shorted to the case. I will be much more careful installing the new one. I opted to purchase a new alternator as I can have it today and it doesn't cost much more than a rebuild (and comes with lifetime warranty).

I'm not sure I'll paint the new one, although since it has a lifetime warranty it could be a good way to test if the paint was the issue...

DGXR

The lifetime warranty may be voided if you paint it.

Bfenty

Good point. I was being [mostly] sarcastic anyway.

DGXR

The virtual world is in desperate need of sarcasm font.

Bfenty

This is wisdom right here.

JimLentz

https://v3b.com/2011/09/sarcasm-love...t-has-arrived/

scrappy76

The way I see it, it was working fine before you painted it, pretty sure something happened, whether it's the paint or the positive insulator cracked or broke when you loosened it or tightened it, or it just decided to cook itself at the the same time frame you touched it. I would say one of the two is most likely the culprit. Best idea you had is to install a new one.

Joe C

so, if you purchased a new unit, what did you do with your "original" core (assuming you had the original assembly)? 108 or 120 amp assembly? if the parts house is only going to give you $10 (typical alternator core charge), sell it here, i'd be interested...

Bfenty

I already gave it to them. Shoot I should've sold it here, rather you guys benefit than them

A Peter C4

Well the new one will be nice and clean, maybe ever shiny, if anything just clearcoat, mask holes and connections don't over do it with clear. Or you could go chrome, polished, or black Jegs or Summit Racing.

xrav22

Hey what is the red stuff on the contacts they should be nice and clean. Time for a new alternator, and a gm alternator rubber cap.
Also the paint won't affect anything people paint their engins the engine doesnt overheat.