Alternators

Nov. 01, 2005 By ORC STAFF
The GM 100 Amp alternator 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 (exciter) connection. It's self exciting and only needs the one wire connection to the battery.

You can get the additional 2-wire connector to connect up the idiot light and field wire. There are two 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:

GM Delco/Remy Original Samurai Wire
2 wire clip Type 1 colors/stripe Type 2 colors/stripe
red white/green black/white
white white/black white/red

Due to higher output of the 100 Amp alternator, 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 alternator). The alternator 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 alternator 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?

Loren's lower bracket 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 alternator 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 ¼") to align with the GM alternator upper bolt.

The GM alternator installs very easily from below. You remove the two screws that hold on the plastic dust shield and slide it out of the way. Then loosen the two 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 ¾") out of your way to slip in the bigger GM alternator

11/96 update: I found a 94 Amp alt from a stock 83 Camaro, 2.5L 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 number 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 alternator. Mine cost $74 from Trak Auto. 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 alternator when tested cold.

1983 Chevy Camaro 2.5L with 94 Amp option Model 7294-3

76 Amps @ 3500 RPM 83 Amps @ 5000 RPM

Two notes that I almost forgot?

On the original 7127 model from Loren, he told me to swap the Samurai alternator pulley onto the GM alternator, so it would spin faster?

Later on when I replaced the alternator (with the Camaro one) I left the stock GM pulley on the alternator, since they seem to be the same size, but maybe I measured wrong.

--Randy G


The Petroworks alternator kit uses a G.M. type CS130 with an output of 105 Amps. There are several configurations of the CS130, but most are basically the same internally with the exception that many of the cheap ones have inferior regulators and diode packs that are made off-shore. Be sure you get the Delco-Remy regulator. It is necessary to use a stronger than stock mounting bracket on the bottom because of the greater load. In addition, the charge wire must be of greater ampacity than the stock harness.

The Petroworks kit includes the alternator, bracket, charge wire, belt and interface cable which plugs into the alternator and into the stock harness.

--Gary Munck


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