alternator replacement with GM type

[68 Sport Satellite]

Hi all,

So I've only had my 68 satellite for about a year and I've had several electrical problems, some of which I have just started addressing. As part of these fixes and upgrades I would like to swap out my original chrysler style alternator for a GM style 10si or 12si type since everyone I've talked to has reported that the GM alternator design is more reliable with higher amperage output. So I've been looking on the powermaster website and talked to their tech guy at length but I'm a bit lost on what alternator to buy.

Has anyone successfully installed a GM style 10si or 12si alternator (internal regulator, 3 wire please) in their '68 - '69 B Body Plymouth? So far I've narrowed it down to 2 choices from Powermaster:

7295 - a GM 12si 100A with V pulley (not sure if it's 3 wire or int. reg)
7127 - A GM OE style 12si 60A 3 wire with internal regulator

However, from the photos on the powermaster website, it doesn't look like either one has the correct mounting bolt holes. My current setup has one hole on the alternator on the left that mounts to the boomerang slider bracket and on the right side it has 2 mounting holes in line with each other, one in the back and one in the front spaced 3 or 4 inches apart with the front mounting hole tab being in front of the 2nd bracket.

Any ideas on whether one of the two above will work or if you have a different recommendation? I defintely want 3 wire, internal regulator with between 60-100A.

Thanks!
--68 Sport Satellite

 

[69HEMICORONETR/TCONV]

a GM Alternator on a Mopar ! :head_smack:......That's like a Blow Job from your cousin, ...it may do the same thing, ....but it just ain't freakin' right ! :no:

 

[68GTX4SPEED]

You better sell that car to me, I will never do things like that, it will come to a good home:yes:

 

[68 Sport Satellite]

Are you guys kidding me??? The stock chrysler alternators are known to be inferior and I have heard only put out about 45 amps. The 10si and 12 si are already being used by many others besides GM. If you know of a Mopar specific alternator 3 wire int regulator that is reliable and puts out good Amperage, let me know your preference. If any on this forum have a different alternator installed, I'm looking for suggestions. All I know is the chrysler electrical system sucks and I want something reliable to match that Mopar horsepower.

Here's a photo of my stock alternator that's in the car.

 

[morbidgoat]

im a little confused here, what would the other two wires be for on a 3 wire "internally regulated" alt? if its internally regulated shouldnt it be a 1 wire alt? on a stock 2 or 3 wire setup from mopar 1 is power the other(s) are for the external voltage regulator hence if your looking for internally regulated you only hook up the one wire and if you are looking for an internally regulated alt summit sells some chrome polished ones starting around 115 i think for a 60amp and if i recall they have 100 amp ones for less than 150 i recently bought the 60amp one but i havent gotten to test it yet

 

[72 Charger SE]

Before you go crazy adding amps to your electrical system with a new alternator, make sure you upgrade another area of your electrical system, namely get rid of your amp gauge and replace with a volt gauge. I would post the link to a good article explaining it if you are not familiar, but I have it saved on my home computer and I'm not at home right now.

 

[68 Sport Satellite]

Morbidgoat -

I thought the same thing as you before I started researching this. Here's a pretty good explanation from Mark Hamilton of MAD electrical. I got a tip for a rewire kit on a different thread from another member of this forum and I've learned a lot. Bottom line - both 1 wire and 3 wire can have internal regulators. The difference is explained below with excerpts from Mark's website:

http://www.madelectrical.com/electricaltech/onewire-threewire2.shtml

In recent years it seems that the term ONE-WIRE has become a much-used buzzword, and ONE-WIRE is often used by people who do not understand it. Among the GM SI series alternators, there is both the ONE-WIRE type and the THREE-WIRE type. Many people who have called did not know that not all alternators with a built-in voltage regulator are “ONE-WIRE” types. Many people simply refer to all alternators with built-in voltage as ONE-WIRE. (Lumping the THREE-WIRE and the ONE-WIRE, both with built-in voltage regulator, into the same classification; is incorrect and results from lack of being informed.)

The difference between the ONE-WIRE and THREE-WIRE alternator is the voltage regulator. The voltage regulator for the “ONE-WIRE” alternator is often referred to as “SELF-EXCITING.” The “self-exciting” terminology probably comes from the old generator days, when testing the generator output required “exciting” the field winding (which involved powering-up the field winding so that it would make a maximum strength “magnetic field”). And the “self” part of the term comes from the voltage regulator turn ON function without the assistance of a dedicated wire circuit.

How the ONE-WIRE Voltage Regulator Works
The iron core material next to the field winding in the alternator will retain some magnetism after once being magnetized with field winding power-up (during assembly). After the engine has been started, and the alternator is spinning, the existing weak magnetic field from the iron core material will cause the alternator to produce a small amount of current. This small amount of current is used to turn the voltage regulator electronics ON (rather than wiring a special wiring circuit to turn the voltage regulator ON). And of course the faster we spin the alternator, the greater the potential for output. That is why sometimes we have to rev the engine once to kick in the “ONE-WIRE” alternator. (We have to spin the field in the alternator fast enough to make sufficient current to turn ON the “self-exciting” voltage regulator.)

How the Three-Wire Voltage regulator works
With the “THREE-WIRE” alternator model built for cars and trucks, one of the voltage regulator terminals is wired to an ignition switched OFF/ON source. The other of the two plug-in wires at the SI series alternator is the “voltage-sensing” terminal for the voltage regulator. Through the sensing-wire, the voltage regulator monitors electrical system voltage and makes adjustments to alternator output. The regulator will adjust alternator output as needed to maintain the place where the sensing-wire is routed (at about 14.2 volts). And the sensing-wire can be routed to a place remote from the alternator (downstream).

This “remote voltage-sensing” feature is often a big advantage when running with a factory type wire harness from the Muscle car period (60’s and early 70’s period cars and trucks). Then the alternator output will be adjusted according to what goes on far downstream from the alternator–at the main power distribution junction, which operates the whole car plus charges the battery!

The Powermaster website also has some great info under the FAQ section for their alternators. I called Mancini Racing today (MOPAR tech and parts since 1972) and discussed the options today. I think I will be buying a Powermaster alternator through them - either the 75A P/N PWM74191 or the dual pulley version of that if they have one. This alternator is 3 wire, internal regulator, with the correct mounting configuration and look for my car. BUT - if I would have just ordered their OE stock replacement, I would have gotten an external regulator type with a measley 45-50A ouput. There are 2 reasons I'm stearing away from the 1 wire type:

1) I've heard that if the alternator goes out, most parts stores don't stock the internal self-exciting type regulator required. The 3 wire type interal regulators are plentiful.

2) The 1 wire type alternator is self-exciting, which means, below a threshold RPM level (I've heard it's between 1200 - 1700 RPM), the alternator doesn't do any charging at all unless you first rev the engine to kick the self-exciter in. You don't have this problem with the 3 wire.

 

[68 Sport Satellite]

Before you go crazy adding amps to your electrical system with a new alternator, make sure you upgrade another area of your electrical system, namely get rid of your amp gauge and replace with a volt gauge. I would post the link to a good article explaining it if you are not familiar, but I have it saved on my home computer and I'm not at home right now.

Great point! Thanks - I'm already on the same page as you. That conversion kit is put out by MAD electrical and I just received it yesterday. I'm doing that conversion plus adding a new 75A alternator all at the same time. Also installing a relay for my wipers. Mark confirmed, as did the Mancini Racing rep, that if I do this and don't go higher than 80A, then I can retain all of the factory wire sizes. If someone goes with a 100A or 140A setup, better up the wire size or you might see a fireball of death under the hood.

 

[Manifold]

I'm surprised no one has put a kit together on this conversion yet (or maybe there is and I haven't heard of it). I was last in the Mopar scene 10 years ago and this was being discussed back then as a solution. Just picked up another B-body recently and was quickly reminded of how lousy the stock alternator/regulator setup is.

Good to see there are way more choices now than 10 years ago. At least now I can afford to upgrade to a nice unit.

 

[74sundance]

a GM Alternator on a Mopar ! :head_smack:......That's like a Blow Job from your cousin, ...it may do the same thing, ....but it just ain't freakin' right ! :no:

:rolling:

 

[beezee]

I'm surprised no one has put a kit together on this conversion yet (or maybe there is and I haven't heard of it). I was last in the Mopar scene 10 years ago and this was being discussed back then as a solution. Just picked up another B-body recently and was quickly reminded of how lousy the stock alternator/regulator setup is.

Good to see there are way more choices now than 10 years ago. At least now I can afford to upgrade to a nice unit.

440 Source has one http://store.440source.com/Alternators-Brackets/products/64/

 

[68 Sport Satellite]

Beezee -

You're the man! Thanks for that part info. Problem is, this is for a big block and I have a 360. I just emailed 440 source to see if it will mount up trouble-free.

---68 Sport Satellite

 

[beezee]

Check out Mancini,s they have small block kits.http://chucker54.stores.yahoo.net/delialbrpk.html

 

[69 Runner]

Those kits have the alternator and brackets, but do they also include instructions on how to wire everything?

 

[68 Sport Satellite]

cool, I was just looking at that same Mancini page yesterday. I think it might even work with my current brackets if I just order the alternator by itself shown on the bottom of the page (P/N MRE6659). I just need to call them to see if this Denso 60A alternator has an internal regulator or not.

 

[68 Sport Satellite]

Well I called Mancini again Friday and the Denso 60A I was looking at is indeed internally regulated and is a 3 wire, so it looks like it would work great for what I'm looking for, however, it won't bolt up to my car without a special bracket which they don't sell. However, the rep told me that Jeggs and Summit carry the bracket. I think I found the correct bracket online, but I need to call them and verify. The saga continues....

Like someone else said on another thread I read this weekend -

Socks are easy.
Eating hot dogs is easy.
Cars never are.

Once I get this all figured out and order everything I need and get it working I will re-post here and let you all know how it turned out. May be a few weeks though because it's supposed to storm and rain all week out here.

 

[Bobs69]

Are you guys kidding me??? The stock chrysler alternators are known to be inferior and I have heard only put out about 45 amps. The 10si and 12 si are already being used by many others besides GM. If you know of a Mopar specific alternator 3 wire int regulator that is reliable and puts out good Amperage, let me know your preference. If any on this forum have a different alternator installed, I'm looking for suggestions. All I know is the chrysler electrical system sucks and I want something reliable to match that Mopar horsepower.

Here's a photo of my stock alternator that's in the car.

I'm with you on this. I'd like an alternator that's going to ensure a good running car.

 

[bbeep71]

Try an alternator from a 1988 Fifth Ave. It is called a 90amp square back and would fit.

 

[Redpolara]

a GM Alternator on a Mopar ! :head_smack:......That's like a Blow Job from your cousin, ...it may do the same thing, ....but it just ain't freakin' right ! :no:

Yeah but she swallows.....well that's what dad and my uncles reckon anyway.:tongue8:

Back to the issue at hand, my car had a GM alt on it when I got it, it just looks wrong.
I'm going with a mini Denso alt with mounting kit......yeah I know, but at least it kinda looks like the Mopar birdcage unit.

 

[68 Sport Satellite]

thanks!

thanks for the 2 suggestions guys! My project got sidetracked with drivetrain work. Then that got finished and I've been attending to some family priorities.

I'll check out the mini Denso as well as the 90amp 1988 Fifth Ave.
Will post progress when I make some!