How to make your G3 alternator a 1 wire connection

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racerjoe

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I'm sure most people that have gotten themselves into a G3 swap without using the factory ECM end up in a situation of having to make the alternator work. I know the old school voltage regulator is supposed to work, but what about the guys who want a clean engine bay? There is certainly an aftermarket resource for a one wire battery connection alternator, but they are pricey. I have a solution to convert your G3 alternator to an internally excited, one wire (battery cable) hook up that costs $50 and about 20 minutes of your time.

Here's how you do it. This is an 06 alternator. Once you remove the plastic back cover, this is what you will see. The brown cover over the shaft contains the brushes for the armature. The two pin connector is basically just a means for the factory voltage regulator to connect to these brushes.

1.jpg


Below the brush holder is removed.
2.jpg


Now the terminal block is removed.

3.jpg


I forgot to take a picture of mine before it was installed, but this is what will be installed. It's a self excite voltage regulator for the Delphi voltage regulators. The part number is IN6324SE. You can find a few places online that sell them. Mine came from a vendor on ebay. Make sure they show "SE" in the part number because there is a IN6324 without the SE. That won't work. SE= self excite.

Note its missing a screw terminal where the original connected to the brushes. That's because this regulator requires one brush to be grounded. Also not the bent tab. That's the stator connection. It's how the VR knows when to turn on. It "reads" the frequency. Lucky for us, the diode plate already has that connection. It just wasn't being used.

vr.PNG


So here's how you install this VR. You will need to drill and tap small hole where the red dot is located. Install the old terminal and mark the hole. I believe all the screws are M4, but I live in America and I use SAE screws...lol. Actually I had some 8-32s so that was good enough.


3 marekd up.jpg


You will also need to make a small spacer to make up the difference of the old terminal used to be. I used a small piece of copper tubing for the spacer. The key is you want a good ground here. I ended up using a 1/2" long screw.

4.jpg



Here is installed. See that small hole in the brush holder? That's so you can stick something in there to hold the brushes back while you slide it over the end of the shaft. I just used a paperclip. Don't force it on or you will break the brushes.

5.jpg



Remember the stator connection I mentioned. This is it. Just solder that connection. The stud off the diode plate is copper and mine was dirty from not being used and being bare copper. Clean that off before you assemble everything so you know you will have a good solder joint.

markup 5.jpg



So here I have the case of the alternator connected to battery negative and the positive on the output stud of the alternator. What you see is just battery voltage.

6.jpg


I spun it up with a drill and the result is obvious. It puts a noticeable load on the drill and lets off when I slow the drill down below it's operable range.

7.jpg



Clearly I don't have any miles on this, but it will be going on my car. I'll order a spare VR and I'll be set to convert a store replacement whenever I need to. This could be done without drilling and tapping if you just ran a ground wire to the brush holder.


The plastic back cover will need to be modified slightly for this to fit.

I hope this helps someone!
 
You should put this in the How To articles section, or maybe the mods can make it a sticky- so it doesn't get lost!
 
I believe I just made it a sticky for everyone, I will see if I did it right.
I did it, my very first and I am glad to help this great sight.
 
I wanted to provide an update on this alternator modification since I now have about 600ish miles on my G3 swap. The voltage regulatory is working perfectly. Just last week I drove to a cruise night 70 miles from home. This was the longest drive at night since getting the car back on the road. With the headlights on and the AC blowing on high it worked just as it should. That's pretty much the largest amp draw the alternator will ever see and its perfectly fine.
 
I'm sure most people that have gotten themselves into a G3 swap without using the factory ECM end up in a situation of having to make the alternator work. I know the old school voltage regulator is supposed to work, but what about the guys who want a clean engine bay? There is certainly an aftermarket resource for a one wire battery connection alternator, but they are pricey. I have a solution to convert your G3 alternator to an internally excited, one wire (battery cable) hook up that costs $50 and about 20 minutes of your time.

Here's how you do it. This is an 06 alternator. Once you remove the plastic back cover, this is what you will see. The brown cover over the shaft contains the brushes for the armature. The two pin connector is basically just a means for the factory voltage regulator to connect to these brushes.

View attachment 1716226882

Below the brush holder is removed.
View attachment 1716226883

Now the terminal block is removed.

View attachment 1716226886

I forgot to take a picture of mine before it was installed, but this is what will be installed. It's a self excite voltage regulator for the Delphi voltage regulators. The part number is IN6324SE. You can find a few places online that sell them. Mine came from a vendor on ebay. Make sure they show "SE" in the part number because there is a IN6324 without the SE. That won't work. SE= self excite.

Note its missing a screw terminal where the original connected to the brushes. That's because this regulator requires one brush to be grounded. Also not the bent tab. That's the stator connection. It's how the VR knows when to turn on. It "reads" the frequency. Lucky for us, the diode plate already has that connection. It just wasn't being used.

View attachment 1716226887

So here's how you install this VR. You will need to drill and tap small hole where the red dot is located. Install the old terminal and mark the hole. I believe all the screws are M4, but I live in America and I use SAE screws...lol. Actually I had some 8-32s so that was good enough.


View attachment 1716226884

You will also need to make a small spacer to make up the difference of the old terminal used to be. I used a small piece of copper tubing for the spacer. The key is you want a good ground here. I ended up using a 1/2" long screw.

View attachment 1716226888


Here is installed. See that small hole in the brush holder? That's so you can stick something in there to hold the brushes back while you slide it over the end of the shaft. I just used a paperclip. Don't force it on or you will break the brushes.

View attachment 1716226889


Remember the stator connection I mentioned. This is it. Just solder that connection. The stud off the diode plate is copper and mine was dirty from not being used and being bare copper. Clean that off before you assemble everything so you know you will have a good solder joint.

View attachment 1716226891


So here I have the case of the alternator connected to battery negative and the positive on the output stud of the alternator. What you see is just battery voltage.

View attachment 1716226893

I spun it up with a drill and the result is obvious. It puts a noticeable load on the drill and lets off when I slow the drill down below it's operable range.

View attachment 1716226894


Clearly I don't have any miles on this, but it will be going on my car. I'll order a spare VR and I'll be set to convert a store replacement whenever I need to. This could be done without drilling and tapping if you just ran a ground wire to the brush holder.


The plastic back cover will need to be modified slightly for this to fit.

I hope this helps someone!
@racerjoe This is great info, and thank you for this. I have this in my alternator, and going to test soon. Question - truly one wire (nothing connected to the black 2 pin)?
 
@racerjoe This is great info, and thank you for this. I have this in my alternator, and going to test soon. Question - truly one wire (nothing connected to the black 2 pin)?
If you’ve done everything I’ve outlined here, there is no connection required on the two pin. Just connect the charge post to your battery.
 
@racerjoe This is great info, and thank you for this. I have this in my alternator, and going to test soon. Question - truly one wire (nothing connected to the black 2 pin)?
I'll also mention that you need to make sure the case of the alternator has a good ground that is common with B-. Modern electronics require many more grounds that are connected to the battery than these cars did back when they were built. My motto for EFI system is, if you think you have enough grounds, add more.
 
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