External to Internal Voltage Regulated Altenator Conversion

[toddtheodd]

This is the "no money spent" (except for the altenator) way to convert your external voltaged regulated altenator for an internally regulated one.

[toddtheodd]

First, you want to go to the parts store and get an altenator off of a 1983 to 1987 silverado. This will have pleny of amps for you, and will hook right up, with a little rewiring.
The little tag on the alt. says;
ULTIMA
01-0260
38039301
One of those is the part number.
Remember that the mounting tabs need to be at a 6 and noon configuration. Some are 6 and 10 or 6 and 2. These will not match up to our brackets. A quick glance to confirm that it will bolt up is all it takes.
It will look like this;

[toddtheodd]

Now for the rewiring.
You have 4 wires running to the external voltage regulator.
blue, white, red, and brown.
Unplug the voltage reg.
Cut the blue and brown wires from the connector and crimp them together.
Like this;

[toddtheodd]

Now the wire bundle that runs to your old altenator from the voltage regulator consists of the Red, White, and Blue wires.

[toddtheodd]

The white wire is now pointless. So terminate it in some way.
I just ended it with a wire crimp.

[toddtheodd]

Now the blue wire, which is just an extension of the brown wire, connects to the tab on the right (number 1 tab). The brown wire runs the the idiot light/gauge in the dash and is there for resistance to the internal voltage regulator. You can not skip this as it tells the regulator what it needs to be doing and when.

[toddtheodd]

Now the other tab on the altenator needs power (tab # 2). And the best/easiest way to do this is with a jumper.
Run the Red wire to the Big post on the back like normal. And then with a short length of wire, run a jumper from the back post to the left tab.
Like this;

[toddtheodd]

That's it.
You're done.
No more problems with external voltage regulators, and plenty of power to run whatever you want.
Todd

[1972C10]

That Price must have came from O'Reamly's Check out Autozone They have it in stock as well.

ALTERNATOR for a
1984 PONTIAC TRANS AM
Normal Stock
Special Order
Not Available



Item Part
No.
Warranty Core
Value Unit
Price Availability
Store Web
DURALAST
94 AMP DL7294 LLT $30.00 $64.99
PREMIUM QUALITY REMAN, SOME NEW COMPONENTS

VALUCRAFT
94 AMP 7294 1 YR $30.00 $54.99
REMANUFACTURED UNIT

[Hotdog]

What about the red wire to the regulator plug? Is it a dead end ?

[Dustmaker65]

Originally Posted by Hotdog

What about the red wire to the regulator plug? Is it a dead end ?

Yes...red and white going to regulator are no longer used.

[Scooby63]

I just bought another project, 1966 shortbed factory 4x4. Hasent been registered since 1999. Runs and drives, has a newer V8 small block (havent run numbers yet, I imagine it is a 350)
Anyway someone hacked up on the wiring when they installed the alternator.
I have everything pretty much sorted out, with one question.

The BROWN wire that comes from the cab harness is 12V when key is on.
The WHITE wire that comes off the pigtail in the #1 tab on the alternator puts out 14V when running.

Are these 2 supposed to be spliced to each other ??????

Reading a few write ups it sounds like I am supposed to connect these 2, but it seems wrong to connect one wire with 12V to another with 14V

[dannyboy1224]

Hey guys, I found this really helpful, but once I got the alternator on I realized that the "fins" for the fan that draws air into the and through the alternator are going in the wrong direction. I pulled this thread up and looking in the picture, your's does as well. This will seriously affect the life of the alternator as it will not be pulling air through it. The engine turns clockwise on these old trucks, this alternator must be made for an engine turning counterclockwise? Thoughts? I'm going to try to find one of these style that is opposite direction.

[DJ_Baar]

Originally Posted by dannyboy1224

Hey guys, I found this really helpful, but once I got the alternator on I realized that the "fins" for the fan that draws air into the and through the alternator are going in the wrong direction. I pulled this thread up and looking in the picture, your's does as well. This will seriously affect the life of the alternator as it will not be pulling air through it. The engine turns clockwise on these old trucks, this alternator must be made for an engine turning counterclockwise? Thoughts? I'm going to try to find one of these style that is opposite direction.

I am doing this along with my complete AAW rewiring of my '67 Chevy C20. Does the direction air flows thru the alternator really matter (pushing or pulling air thru the alternator)? AAW recommended same alternator with one wire conversion.

R/
DJ

[VetteVet]

This was one of the first conversions posted on the forums and it made it's way to the FAQS where most people can access it. While it works, there are better ways to do it. It does not take into account the voltage drop down stream of the alternator, because looping the no.2 voltage sensing wire directly to the alternator output wire does not account for the voltage drop down stream in the circuits away from the alternator. This can result in as much as a 2 volt drop in volts loss to the system loads.

It is easily remedied by the method I use and recommend shown in the diagram below.
Simply extend the brown wire from the external voltage regulator to the no. 1 terminal on the SI alternator, and extend the red wire from the external regulator to the no. 2 terminal on the alternator. The red wire connects to the main system junction of the truck circuits and is able to sense the voltage draw on all the truck loads combined. This allows the alternator to output voltage for a longer period to deliver a full 15 volts to the truck circuits.

Here is the wiring for the stock OEM truck




Here is my conversion for the SI internal regulated alternators. Use the 12 SI from the mid eighties GM vehicles. following the directions I gave, you can delete the regulator harness and the blue and white wires, although you can use them to extend the brown and red wires. Of course you'll have to use an adapter to connect the wires to the alternator.



And if you want a real improvement you can put a 75 to 300 ohm resistor in the brown wire and run it to the L terminal on a more modern CS alternator, and run the red wire to the S terminal on that same alternator, and you have a more powerful alternator, and a much more available unit than the SI models.
The 12 SI is a very good unit and even the 10 SI is bettter than the old externally regulated stock unit.



For the curious the alternator pulls cooling air from the rear so it's a bolt on and go deal. The CS models just require the resistor and changing the front pulley to belt drive.

[dannyboy]

Thanks Toddtheodd, that's the way to show and explain this conversion. Simple to the point.
Confirmed what I thought I remembered how to do, you know you don't use it well you loose it, some place in the back of your brain. Its getting it through all the other misc things back there that's tough.
THANKS

[63C20]

Originally Posted by Dustmaker65

Yes...red and white going to regulator are no longer used.

ok im still having issues, i see nowhere it says to end the red wire, looks like it goes to the fuse block/battery??

[Hinz28]

Did exactly as the OP last night. Battery was dead this morning

[64.2.restore]

I know this is an old thread but I'm damn glad it was here saved me a lot of headaches i send thanks to the guy who posted the info

[jcramsey]

Looking to do this in my 62 c20 right now. I've got the brown wire coming from my generator to the regulator (middle terminal in pic) but no brown wire from the regulator to the firewall connection. Would the red wire tied into the same terminal as the brown wire on the regulator be my indicator lamp wire?

[Jack15T]

Hey Todd, I am about to install a painless wiring harness in my 1971 Chevy K20 pickup. It currently has an External Voltage Regulator. What are the advantages to converting to an Internally Regulated Alternator. Thanks, Jack

[vince1]

http://67-72chevytrucks.com/vboard/s...=763180&page=2

Lots more to read

[Jack15T]

Thanks Vince.

[headsup9550]

I don't have any pics but I always take the external regulator apart by drilling 2 rivets that hold the black cover to the silver mounting bracket. Inside there are 4 posts that the circuit board is soldered to. Break this board off the lugs with needle nose pliers and get two 3 inch pieces of 12 gauge wire with the insulation stripped off of the ends and solder one from post 1 to post 3 and one from post 2 to post 4 and reassemble with two #8x½" machine screws, reinstall and plug the harness connector back in. This way there's no need to butcher the factory harness, no unsightly jumpers hacked into the unplugged, loosely dangling connector and you get cool points for a couple of obvious reasons..

Adam

[Jack15T]

Originally Posted by headsup9550

I don't have any pics but I always take the external regulator apart by drilling 2 rivets that hold the black cover to the silver mounting bracket. Inside there are 4 posts that the circuit board is soldered to. Break this board off the lugs with needle nose pliers and get two 3 inch pieces of 12 gauge wire with the insulation stripped off of the ends and solder one from post 1 to post 3 and one from post 2 to post 4 and reassemble with two #8x½" machine screws, reinstall and plug the harness connector back in. This way there's no need to butcher the factory harness, no unsightly jumpers hacked into the unplugged, loosely dangling connector and you get cool points for a couple of obvious reasons..

Adam

Thanks Adam. I’ll look at it. Jack
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