YOu need to look at the alt where the plug connects to it. if there's 4 pins in there you can get the other plug for it at most auto parts stores.

IF THERE'S ONLY ONE WIRE that wire can be hooked to the back of the alternator to the main output plug or hooked to a source that sees 12 volts when the ignition is on wether the engine is runing or not

If it has the 4 pin plug then "S" is source or a wire to the main vaoltage distribution block (can also go to battery but isn't ideal)"L" goes to the dummy light or any lamp with a resistor added when needed to get the resistance between 300 and 500 OHms. "I"is ignition or basically a 12v source that comes on when the car is turned on. "I" is used to tell the alt to start charging when the ignition is on, "L" also is used to the same purpose and tells the thing to start charging when the light goes out. "S" is for sensing voltage levels to tell the alt how much power to put out. And "P" is phase and is used to send a dignal to a relay or tachomoter and in any DSM sitation is NOT used..

Beingthat you have the one wire alt uses the one wire to tell it to start chargin, it has not "voltage sensing" feature and is known for voltage issues, and is mainly only good as a "battery charger" ebcause it doesn't deal well with the added loads of ehadlights, radios and the like..also known for making ignition systems weaker because of poor voltage supply

here's a quote from one of the best wiringsites i know of

The ONE-WIRE, without REMOTE VOLTAGE-SENSING option, as an "intended up-grade" from a 55Amp externally regulated to a 100Amp ONE-WIRE can result with dim lights, weak ignition, and weak performance in general. (Especially so when a factory-original" type wire harness system is used.) And at M.A.D. we have received many phone calls from people who have experienced the result of such conversions.

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Here';s a good read about the advantages and disadvantages of the one and three wire systems..
Catalog

and here's a small quote from that site again about why the one wire alt's aren't that great on modern cars especially with all of our added electronics compared to cars of the 60's and 70's

The remote voltage-sensing feature is not available with "ONE-WIRE" alternators. With the ONE-WIRE alternator, the internal voltage regulator can only adjust voltage at the alternator. To show how the ONE-WIRE alternator would behave in this test, we let our existing THREE-WIRE alternator take voltage-sensing sample from the output stud at the back of the alternator. Then voltage-sensing with our existing THREE-WIRE alternator would behave the same as with a ONE-WIRE alternator.

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http://www.madelectrical.com/electricaltech/remotevoltagesensing3.shtml

Perfect! I was hoping to get a reply from you Glenn
I read through the whole thread on your improvement and didn't really see what I was looking for.

There are 4 pins under there so I guess I'll be getting a new pigtail for it and going the improved route. But all of that is a long ways away seeing as I can't get the alternetor to tension properly.... Perhaps more grinding is in need?

Yea, might need more grinding if it binds in the travel.. What i did was took an 80 grit roloc and ground on the engine block and front cover where they meet and make up the mounting point. grind themto where the materail around the holse for the alternator base is around 3/8th of an inch or so and it makes the alt needminimal work and it doesn't ttake too much away from the block and cover

Got it installed and it's working great. No new wires ran yet (waiting for that other harness before I go that route) and I'm getting 13.8V at idle with HIDs and fans.

The issue with the mounting was the oil cooler. I had to take a fair amount off of the alt housing, but not enough to compromise it's structure. For the block, I tried using a dremel, but there wasn't enough room to work with, so I just ended up borrowing a small angle grinder to clean it up. Worked nicely.

Only Issue was when I tried to tension it..... MacGyver Win?
Med pry bar on the block, and just ripped those ties tight!

Glenn - Are you still in the business of making those brackets?

Anywho, I'm going to try and venture through your thread again as I recall someone mentioning a whinning sound coming from the Alt when the car is off. I have that for sure, just want to make sure it won't kill my battery over night.

Any chance you have a part number for that 3 wire plug??
I'm from Canada and we can't track one down :/

This is the alternator I have.
http://images.wrenchead.com/smartpages/partinfo_resize/DUS/334-2476.jpg

And this is the plug it has....

Sssioooooo...... Did I just blow 90 on the wrong alternator and grind it? Or is there a way to salvage this?

I've been running around all day but can't find a compatible pigtail...

http://www.jayracing.com/images/products/2010 GM Pigtail.jpg

??

johnovision27 said:

ght!

Glenn - Are you still in the business of making those brackets?

. I have that for sure, just want to make sure it won't kill my battery over night.

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+1 on this. Lost track of the other thread

Just as an update, I was frantically writing that last post before my phone died.
Now, the pigtail I put the link up for is the one that I believe everyone is after. That won't work with my alternator. However, I came across another version of my pigtail that has 4 wires on it. The alternator does list the S, L, F, and P pins. I think I'll just pick up that other pigtail and make it work with this alternator seeing as I'll never get my money back for it now.

Also messed up on the last picture. It was suppose to show that there is only one wire coming from the harness in what I believe to be the L spot. But, I'm sure you can tell that from looking at the plug front.

So, Glenn.... What are you thoughts on this? It is an alternator from a Saturn SC2 '99. Bolts up fine and charges fine. What about the wiring? Should work the same?

Should maybe update this.
Just hooked it up to the stock sense wire and everything has been running great.
Pictures also reminded me of the zip ties holding the alt in place, I really should fix that....

did you ever got the pigtail for the alternator or did you only use the 1 wire,
i got one of this for free and I'm just wondering everything going, it seems that not many people run this type of alternator