GM 100 Amp Alt

The GM 100 amp alt. that fits in a Samurai (that was sold by Loren) is a GM 7127 model. It doesn't need the idiot light connection or the Field (excitor) connection. It's self exciting and only needs the one wire connection to the battery. Also will need to swap the pulley from the Samurai alt onto the GM alt, so it spins faster at idle.

You can get the additional 2 wire connector to connect up the idiot light and field wire. There are 2 possible color combinations of Samurai wire harness depending on the year. (Sorry still haven't noted what year is which.) The color codes of the wires for proper hook up are:

Due to higher output of the 100 amp alt. it is recommended that a 30 amp fuse be put in place of the approx. 6" green wire (fusible link) at the positive battery post, which comes from the stock wiring harness (and is connected to the amp). The alt. is capable of charging the battery at more than 30 amps if you have too heavy a draw. I think a battery shouldn't be charged with more than 30 amps, even on a quick charge. So the fusible link is there to protect the battery AND the stock wiring harness.

You don't have to install the 30 amp fuse, but it's safer and easier to do it now. If you don't have a 30 amp fuse, the fusible link at the battery will blow and you'll need to splice in a piece of wire to replace it. If this fuse (or fusible link) blows, the car will die completely. (A fusible link is a wire 2-4 sizes smaller than the wire it protects.) This wire is needed for the entire car to work, SO CARRY SOME SPARE 30 Amp FUSES or WIRE.

The stock Samurai alt. puts out 45 amps. A sidekick puts out 55 amps (I think. It may only be 35 & 45). I've installed the 100 amp GM alt with just the one wire hook up and it works fine. Later on I taped off the original Samurai 10 gauge wire at the alt and ran a 6 gauge wire from the alt to the positive battery post. You don't have to do this, but the fusible link (or 30 amp fuse) at the battery pos. will blow, if you have lots of accessories drawing more than 30 amps. When this starts happening, it should be a warning signal to you, to install the 6 gauge or large wire. The fuse is blowing cause the stock 10 gauge wire in the stock harness can NOT carry the additional output demand of your accessories (now that you have an alt than can output more and keep up with the accessories), and it is protecting itself from a melt down...

The lower bracket (of Lorens) fits like a charm. It's a Samurai bracket, with the original extensions cut off from the base. Then new pieces, to hold the GM alt., are welded to the stock base. So the old Samurai base bolts right in. You reuse the upper bracket that is currently there. Just loosen it so it moves (about 1/4") to aligns with the GM Alt. upper bolt.
The GM alt. installs very easily from below. You remove the 2 screws that hold on the plastic dust shield and slide it out of the way. Then loosen the 2 bolts ON the passenger's side of the radiator support bracket, that hold the lower radiator hose's brace; as you'll need to push the lower hose (about 3/4") out of your way to slip in the bigger GM alt.

11/96 update: I found a 94 amp alt from a stock 83 Camaro, 2.5 l engine, 94 amp option. It is GM model #: 7294-3. (The "-3" means the 2 wire connection is in the 3 o'clock position. You have the choice of 3, 6, 9, & 12.) I also know there is a 110 amp version, but can't seem to find the model # yet. It comes stock at 94 amps and is available from any auto parts store. This makes it way cheaper to purchase than a juiced up specialty alt. Mine cost $74 from Trak-Auto. And I left the stock GM pulley on the Alt this time, since they seem to be the same size anyway, but maybe I measured wrong. You can also buy the GM 2 wire connection for the alt at most parts stores too. So now all you need is to build or buy the bracket.

Here are some specs, I got on the output of the GM 94 amp Alt, when tested COLD.
1983 Chevy Camaro 2.5l with 94 amp option Model #: 7294-3
76 amps @ 3500 rpms 83 amps @ 5000 rpms

1/29/98 update:
------------------------------
Date: Wed, 28 Jan 1998 21:48:46 -0700
From: William Johnston <billjohn@elpasotx.com>
Subject: Re: Will J's 135 amp alt???????

suzuki4x4
>I did the dual battery/isolator thing after dropping in a GM model 135 Alt.
>(I think it runs 105-115 amps). I eventually had to modify brackets and to
>compensate for the heavier, larger unit. I also rewired the connector, it's
>certainly is worth it.
><< Will ) )
>
>Hey Will,
>Do you know the model number of that alt? OR the year make and model of
>vehicle it came out of?

I actually had a local shop do the original install. Although they put in the
alt and had it running, I ended up having to upgrade the wires (they got hot)
and modify the brackets (they used lots of washers, longer bolts and left out
a bolt). They told me it was a GM model 135, and because it was brand new, I
don't know what it was originally intended for. There are only a few off-road
shops here in El Paso, and I am now a firm believer that they are only doing
work for those folks with driveway queens and not folks that thrash in the
desert. This is probably not really true, but I haven't found anyone here to
prove me wrong!

=8^1
====================================
Bill Johnston
El Paso, Texas
billjohn@off-road.com
http://www.off-road.com/4x4web/suzuki
------------------------------
------------------------------
Date: Wed, 28 Jan 1998 11:26:00 -0500 (EST)
From: "Clive Apps Techno-Logicals 416 510 0020" <clive@problem.tantech.com>
Subject: Re: Will J's 135 amp alt???????

> Hey Will, (I think this was to: William W. Harris <wilcowil@gte.net)
> Do you know the model number of that alt? OR the year make and model of
> vehicle it came out of?
>
> The best I found so far is a 94 amp out of a 84 Camaro. My parts counter
> guys aren't to smart, and I can't help them... What's that say about me? ;^D
> Take care, Randy

try any mid 80 GMC van 3/4 or 1 ton, they came with up to 160 amp alts.
Clive
------------------------------


05/01/98 update, from talking with todd G. reading from a book
------------------------
His book referenced 2 types of alts, Internally regulated and Externally
regulated.

INTERNAL Regulator
------------------
The 2 post should be labeled 1 & 2.
1 = Excitation post. should be connected to a switched power source, so that
it is ON when the key is in the ON position.
2 = Battery Sensing wire... Should be connected to the battery. It feeds
back to the regulator, indicating the actual voltage at the battery...
As the wires when hot will drop voltage, and the regulator will
compensate for this.


EXTERNAL Regulator
------------------
The 2 post should be labeled F (like # 1 above) & R (like # 2 above).
F = Excitation post. should be connected to a switched power source, so that
it is ON when the key is in the ON position.
R = Battery Sensing wire... Should be connected to the battery. It feeds
back to the regulator, indicating the actual voltage at the battery...
As the wires when hot will drop voltage, and the regulator will
compensate for this.


Currently on my sammy, I keep burning up alt, BECAUSE both my wires are
putting out 11 volts... So the # 2 wire is constantly telling the Alt to put
out more voltage, as it should be in the 13.7-14.2 range. Thus my alts
getting hot, bearing burning up, battery boiling over, etc. Nice bright
lights though, even at idle... ;^D

Also feed back to dash battery light causing low glow, which gets brighter
with more drain, this is because a small amount of current is now flowing
the opposite way, like a shorted ground.
------------------------


05/05/98 Update....
------------------------
Item 0011670 sent on 98/05/05 15:59
>From RANDYG
To: SUZUKI4X4-DIGEST@UNIX.OFF-ROAD.COM@INTERNET# Post to list SAM---SUZUKI,Mailing list
suzuki4x4-l@avenza.com@internet# Post to list SAM--Suzuki-CANADA,Mailing

cc: pglyph@primenet.com@internet# Scott SAM-Gomez,4x4 Samurai page Adm
loren@netway-i.com@internet# Loren SAM-Hantsbarger,High Country Outft

Hey gang,

I got some updated info on the write up for the GM alt installation, found at
the web site in my signature...

AND IT'S KINDA IMPORTANT IF YOU FOLLOWED WHAT I WROTE...

I never tested what I was told on the wiring and just retyped it.. But after
many years of burning up alts and 1 toasted battery.. I finally figured out
my problem.... and so I'm posting to the list, to let you folks know..

It may just pertain to MY vehicle.... sooooo... I need some feed back if
you care to.... Cause I'm not sure all sams are the same... (I don't have
the luxury of multiple running sams in my driveway, like some of you... ;'^D)

The basics of the wiring say to connected the "ignition on" wire (black with
white tracer in an 87) to the Reference or #2 connector (red wire on gm plug)
and the "dash lamp" wire (White with red tracer in an 87) to the #1 or Field
connector of the alt... (think I got that right.)

terminal GM 2 Original
marking wire Samurai wire
on GM clip colors/stripe Function in stock
Alt case 86-88 models later years Samurai
------- ---- ------------- ------------- -----------------
#2 or R Red Black / white White / green ignition on wire
#1 or F White White / red White / black dash light wire


On my vehicle.... NEITHER of these wires puts out more than 11 volts. So
consequently, the alt (and might I add 4 destroyed alts) kept trying to up
the voltage to achieve the 14.2-14.7 or so which is suppose to be at the
battery.

In doing this, the alts were constantly running at full bore till they burned
up from excessive heat..., being as the reference wire never showed 14.2 only
11, the alt thinks the battery is only getting what it sees on the reference
wire (11v in my vehicle).

Not to mention the batteries that have prematurely died, due to 15.1-15.5v
volts CONSTANTLY being shoved at them from these alts... This is what alts
are capable of putting out.

ON the plus side... I might just add... that I always had really nice bright
lighting in my vehicle... compared to others... 15.5v does brighten things
up... Nor did any of them ever dim when at idle... (I found out how to
wire for this condition, without hurting the battery. (just one more thing to
think about doing.)

My solution was to pull the "ignition on" wire from the alt's reference
connections and run a reference connection directly to the battery, or the
main FAT wire that runs current to the battery, as there should be no drop on
this line... I just taped off the stock "ignition on" wire...

But all this leave me curious, why don't I have 14+ volts on the "ignition
on" or the "dash lamp" wire at the alt? or how did the stock alt do it with
low voltage on these (if that is correct)? or what did I screw up in my
wiring to cause this low voltage????

Appreciate any feed back from any of you running GM alts... test the 2 wires
in that big green plastic plug that went into the back of the sammy alt,
while the engine is running and the alt is cranking out juice... let me know
the color of each, and the voltage on them...

By the way I used the "lamp" wire for the Field (#1) post connection, so that
the dash idiot lights (sensor & bat) would work. doing it this way, makes
the bat dash light glow, ever so slightly at night... the more electrical
drain the brighter it gets.. but is always dim, and only noticeable at
night... (and this is because there is a small amount of current running
through this circuit to up the field current in the alt., which in turn, ups
the amp output of the alt.)

Another note.. if you swap (well, when "I" swapped) the connection of the 2
wires. the car didn't shut off, when the key was turned to off and
removed... that was sorta nifty... so I don't think it can be wired any other
way...


Take care, Randy
------------------------


5/06/98 update.....
------------------------
>From jjpsuzq@mailhost.day.ameritech.net Mon May 4 22:48:54 1998
Date: Mon, 04 May 1998 18:52:55 -0400
From: Jeffrey Pollock <jjpsuzq@mailhost.day.ameritech.net>
To: randyg@geisnss1.geis.com
Subject: Re: Re2: drag links & steering for

Randy,

The part number for the 94 amp alternator is...

At Parts America N1-266. It's from a 87 Chevy Caprice with a 350. He
does, however, show a listing for a 108 amp but it's a special order and
I'd have to pay for it for them to get it. My friend at the parts store
said that the 108 amp alt. has a bigger housing. Hope this helps.

Jeff
------------------------

--Randy G

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