Can anybody identify this GM alternator?

SteveD2 · Dec 10, 2004

I got this alternator for cheap, I'm going to make a welder out of it. I want to rebuild it first, but I have no idea what kind of alternator it is. All I know is that it's huge and from a mid 80s GM vehicle.

Here it is next to a newer "CS130" alternator, just so you can see how big it is.

The only number stamped on it is this "100" under one of the mounting holes, does that mean it's 100 amps?

TomH · Dec 10, 2004

It looks sort of like this one off of a mid 80s Cadillac diesel, with a slightly different pulley fan.

http://www.partsamerica.com/PartDet...e=QLT&MfrPartNumber=P7157&PartType=11&PTSet=A

And yes, I do think that one is a 100 amp model.

SteveD2 · Dec 10, 2004

It does look alot like that one, although it's hard to tell if that one is the big version or not. As far as I know, the "SI" alternators are identical except for size and amperage output. Would it really be that difficult for them to stamp a part number or the word "amps" on it?

Chris142 · Dec 10, 2004

Looks like a Lester #7135 if my memory is still working.

EmbarkChief · Dec 10, 2004

I'll wager its out of a diesel.

tom slick · Dec 10, 2004

27 SI maybe?

wwillson · Dec 10, 2004

Looks just like the alternator on the 6.2L diesel.

BTW - how do you make a welder from an alternator?

Wayne

Gary Allan · Dec 10, 2004

quote:

how do you make a welder from an alternator?

prefabbed setups

SteveD2 · Dec 10, 2004

quote:

Originally posted by wwillson:

BTW - how do you make a welder from an alternator?

I'm making my own regulator that will let set the voltage and the amperage to whatever I want. It's going to be hooked up to a 7.5hp engine...I'll be able to use it for welding, jump starting, and power generating with my inverter.

So does everyone here agree that the "100" means 100 amps?

Gary Allan · Dec 10, 2004

IIRC, that was a GM notation techique. You would see a 10SI or pre 10SI ...tip it around until you found a # stamp (I think 40 and 60 ..maybe 42 and 63 were some very old ratings).

SteveD2 · Dec 11, 2004

quote:

Originally posted by Gary Allan:
tip it around until you found a # stamp

That "100" pictured above is the only number on the whole thing. That other CS130 in the picture doesn't even have that much stamped onto it. You'd think they would want some sort of part number on them for identification in parts houses.

tom slick · Dec 11, 2004

I'd bet it's a 100 amp. those larger framed alternators were rated, at the lowest, 100 amps or more. you may need a heavier duty rectifier to up the duty cycle.

take a look at alternatorparts.comthey carry alot of heavyduty parts at reasonable prices.

what welding rod do you plan to run with this setup?

SteveD2 · Dec 11, 2004

quote:

Originally posted by tom slick:
take a look at alternatorparts.comthey carry alot of heavyduty parts at reasonable prices.

what welding rod do you plan to run with this setup?

I sent them an email with the pics...hopefully they can identify it. I don't know what rods I'll use with it yet, I'll probably get a few different sizes and see what works best.

Does anybody know what the difference is between the 15SI, 17SI, and 27SI alternators? Does the number actually mean anything?

Can anybody identify this GM alternator?

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