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Discussion Starter #1
Can anybody out there tell me what i have to do to convert my old style GM alt to one wire ?
 

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Discussion Starter #3
Where do I get one?
 

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If it has the two terminal plug setup and the hot lug on the back.....

Run your hot wire (from 12v source) to the hot lug on the back of the Alt.

Then run a smaller jumper wire from that lug to the #2 spade on the two plug terminal (eliminate original plug).

You do not need to run anything to the #1 terminal unless you want your idiot light to work. It hooks up to #1.

I have done this in the past with success..

Warren..
 

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Discussion Starter #6
If it has the two terminal plug setup and the hot lug on the back.....

Run your hot wire (from 12v source) to the hot lug on the back of the Alt.

Then run a smaller jumper wire from that lug to the #2 spade on the two plug terminal (eliminate original plug).

You do not need to run anything to the #1 terminal unless you want your idiot light to work. It hooks up to #1.

I have done this in the past with success..

Warren..
I thought there was a way to do it,i'm goin out to the shop in a bit ,thanks
 

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What Warren said is correct. It won't charge, however, until the alternator reaches a certain rpm point. So make sure and blip the throttle before you write it off as failure.
 

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Discussion Starter #8
Thanks for the input people, what rpm is required for the alt to push juice?
 

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I think the typical ratio of standard pullies is 3:1. When I used to run an alternator, I'd blip the throttle to 3k once and it'd start putting out power (per the volt meter). Ray might have a better answer over in the electrical forum. It all depends on the pulleys and the way the stator is wound.
 

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I put a GM single wire set up on one of my old tractors and the RPM I had to hit was 600 on it and it would start charging...
 

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The jumper wire from the hot lug excites the 'field' in the alternator causing it to start charging. RPM varies depending on the way the unit is wound. Usually not very high.
 

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If your putting that one wire alternator on a race car, you need to make sure the wire from the alternator lug goes to the open side of your external shut down switch, not the same 12 V source that feeds your ignition switch or it will not pass tech, and the external shut off will not work....:smt102
 

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The jumper wire from the hot lug excites the 'field' in the alternator causing it to start charging. RPM varies depending on the way the unit is wound. Usually not very high.
On my set up,I did not have to put a jumper wire on,just bought the self exciting regulator and all I had to do was run a wire to the battery for charging...
 

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First off, on a modern race car you should likely not be using the old style GM alternators. They have button diodes which can and do allow voltage spikes of up to 200 volts into your system. So they can wreak havoc on things like your MSD ignition. Highly recommend going upto a CS130 or CS130D based alternator. These alternators also produce more amperage at idle than the 10SI did at full rpm.

With that said, here is how you convert an older style GM alternator to one wire. You have to take the alternator apart and replace the regulator with an "SE" (self exciting) regulator. During this replacement there is a wire wound resistor going from one brush screw to the ground screw on the regulator. You must leave this resistor out when installing the SE regulator. After you put the alternator back together, you may have to touch a test light to the prongs while the alternator is spinning, and connected to a battery, to get it to turn on the first time.

After that, as long as the alternator is connected to a battery, it will turn on usually once it hits around 3000 rotor rpm. So aftermarket manufacturers have gotten that down lower. And there is an aC turn on regulator that will do it around 1500 rotor rpm. But this is all old school stuff, mostly just good for tractors now.

The running of jumper wires will not turn your alternator into a one wire. A regular regulator in the older GM has a sense wire, that only tells the regulator what the voltage in the battery is, and a light wire. The light wire turns the alternator on and off. If you put a steady 12volts to it, you will have your alternator turned on all the time.

hope that helps.
 

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Discussion Starter #15
THANKS FOR THE INFO GUYS.
 
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