Javelin GRM+ Memberand MegaDork
1/19/13 12:35 p.m.

The original 65-amp alternator in the Javelin died and my late-80's one on the shelf from a 401 Wagoneer isn't even remotely close to fitting. Any ideas? I'd like to utilize the original brackets, but have no issues with re-wiring. Original is externally-regulated, so an internally-regulated one would be great (1-wire GM hookup).

GameboyRMH GRM+ Memberand PowerDork
1/19/13 1:08 p.m.

The 78-amp or 100-amp GM alternators are a popular upgrade on Samurais.

Javelin GRM+ Memberand MegaDork
1/19/13 8:52 p.m.

Anyone? The AMC guys all swear by a metric 3-wire 100 amp GM unit, but involves major bracket surgery. I found the 1980 Wagoneer HD unit is at least a 7o amp unit. Oh, and my stocker is 55, not 65.

Ranger50 UberDork
1/19/13 8:58 p.m.

What is it a mid 90's Chevy truck for a 1-wire?

curtis73 GRM+ Memberand UltraDork
1/19/13 9:10 p.m.

Wait... aren't AMC alternators the same Remy/Motorola style? I would think any 10si alternator should bolt up, right?

curtis73 GRM+ Memberand UltraDork
1/19/13 9:11 p.m.

Yeah.... Here:


wlkelley3 SuperDork
1/19/13 9:16 p.m.

Is there an electronic shop around there? I had the original alternator in my Opel GT rebuilt and they increased the amperage on it when they rebuilt it. It involves replacing a diode inside with a higher capacity one. Any electronic shop that rebuilds alternators can do it.

stuart in mn
stuart in mn PowerDork
1/19/13 9:34 p.m.

Do you really need an upgrade, or just a replacement? The original one lasted for 35 years or so, I'd assume a replacement should last for another 35 years.

As far as that goes, what happened to the original? Nine times out of ten all they need are a new set of brushes and maybe bearings, for a few bucks you'd be back in business and there would be no rewiring or bracketry required.

Javelin GRM+ Memberand MegaDork
1/19/13 10:36 p.m.

In reply to stuart in mn:

The originals are not known for their longevity, and it's probably been dead since long before I got the car. 55 amps also won't be enough for the future modifications (electric fuel pump, EFI, etc).

Javelin GRM+ Memberand MegaDork
1/19/13 10:48 p.m.

Double correction. My original unit is a 37 amp. I do not have the HD unit.

My replacement one is a 10si. It's a 13-4011 Delco 66amp. Apparently I just need a pigtail, some drilling, and some bending to get it in.

stuart in mn
stuart in mn PowerDork
1/20/13 9:28 a.m.
Javelin wrote: 55 amps also won't be enough for the future modifications (electric fuel pump, EFI, etc).

Okay, that's a good reason. I see lots of people who go to a lot of trouble putting in higher power alternators in old cars, but since they aren't making any changes to the rest of the electrical system the bigger alternator doesn't do them any good.

Javelin GRM+ Memberand MegaDork
1/21/13 5:51 p.m.

Well crap, my 10si is such a physically larger size that even if I modified the brackets, it would hit the oil filter before coming into adjustment.


tpwalsh Reader
1/21/13 5:58 p.m.

In reply to Javelin:

shorter belt?

81cpcamaro HalfDork
1/21/13 7:23 p.m.

Any adversion to the newer CS105 style? I picked up a 92 454 TBI from a Suburban and its alternator has the same bolt spacing as a 10si in a Chevy application, but is a smaller case size. Pretty easy to wire up using an adapter plug.

Javelin GRM+ Memberand MegaDork
1/21/13 9:17 p.m.

In reply to 81cpcamaro:

None at all. Thanks for the tip!

In reply to tpwalsh:

Not going to help. The alternator case itself is too long (deep) and wide (circumference). The oil filter is below and behind it at an angle.

dean1484 GRM+ Memberand UltraDork
1/21/13 9:43 p.m.

Have you looked in to having your OE unit rebuilt and at the same time upgraded? I have a local guy that re builds starters adn alternators and will upgrade them to higher amps.

Javelin GRM+ Memberand MegaDork
1/21/13 10:49 p.m.

In reply to dean1484:

The 37-amp (and 55-amp HD) Motorola unit is not a very good design, and is extremely expensive to rebuild due to NLA parts. Even if it could be done, it wind up being way more money than even a fancy MSD or Powermaster conversion.

Javelin GRM+ Memberand MegaDork
1/22/13 3:50 p.m.

Well, I spent some serious time with the alternator interchange books from my old employer today and figured some stuff out.

The 10si and 12si GM alternators (like my spare, and what AMC used from 1975-on) require the later AMC/Jeep brackets, period, end of story. There is no mythical small/short case that will clear the oil pump and filter in the factory 74- brackets.

Switching over to anything else (Ford, etc) wouldn't work, either, without a complete bracketectomy. So, some digging around for something with the interchange to the 37-amp Motorola gave me a low-and-behold moment. The alternator was originally designed for tractors! Using that we were able to interchange to a fresh rebuilt unit for a massive John Deere for $66 (with a $2.50 core charge, so I'll be keeping my "matching numbers" alternator, too) that's a 55-amp unit.

It gets here this afternoon. Fingers crossed...

pres589 SuperDork
1/22/13 5:07 p.m.

Yeah, my dad's 2510 has a Motorola alternator on it, the thing never has given any problems to my knowledge. Oddly, his 3020 is a couple years newer and came with a Delco generator. Curious what model JD your Motorola alternator is meant for, you say massive, so an 8010 perhaps?

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