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Single wire alternators

15243 Views 39 Replies 6 Participants Last post by  GypsyR
These internally regulated single-wire alternators are sounding pretty good. Would I have to change any wiring to make it work or is it all pretty straight forward as if I were installing a factory alternator?

Also, I assume these internally regulated units have the condensors inside as well?
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One Wire vs. 3 Wire

The 3G alternators are superior in every way! :smoke:
OK, well I'm certainly convinced to go with a stock 3-wire, but that site says that all alternators are internally regulated(Wrong!). I'm pretty sure anyone that owns a classic Mustang can point out that ugly box in their engine bay.
Actually that page is focused solely on Delco (Chevy) 10 and 12si alternators. These are the alternators people like Powermaster are converting to "one wire" functionality and the MADelectrical people are giving their opinion on why this isn't the best idea.
I like 3G's, even if thay aren't real "1 wires". One wire to the battery and another "exciter" wire. The exciter wire can be hooked to an ALT indicator light which suits the heck out of me anyway. You just make wiring mods to hook a 3G to your vehicle, you're not changing the way Ford intended a 3G to be connected .
The low voltage readings at full load on my Bronco always bugged me so one day I pulled it's perfectly functional 75 amp 2G and stuck a 130 amp 3G on it too. Voltage now stays at 13-14 volts no matter what I do.
I added an alternator warning light to my 67 Mustang and it's 3G works just fine too. Wife's 86 Mustang 3G swap was even easier.
The 3G's I use are OEM 1996 Mustang 3.8 alternators. When the 100 amp 1G on my F100 goes out I'll stick a 3G in it too.
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What is a 3G? You keep saying that. LOL, pardon my ignorance but I haven't got a clue.

What's wrong with just buying a stock regular 100 amp alternator and hookin up to my stock wiring?
Stands for 3rd generation.

Most of the one wire alternators sold are a GM design.

Pre '94 Mustangs had the 2G and it was used for many years. They do not put out much current a idle or low RPM. The 3G puts out about 70AMPS at idle! That is why you see so many posts about using them on older Mustangs.
Alright, well what about something like this:

I guess I don't get why I can't just buy a stock alternator for my car like that one(or I assume it to be). I mean I obviously wanna go with more current than my stock alternator, but I don't see what's wrong with whatever the original wiring configuration was(I assume 3 wire?).
Everything you need to know about the 3G

Attached is the document that I used to convert my 65 to the 1 wire 3G. I also used their harness that is offered in the article and it made life even easier. The only issue that I have had is a squealing belt. The 3G is designed for a serpentine belt. If the belt is aligned perfectly and very tight, a V belt will work.


LOL, I just wanna put a stock style alternator in my car(with a higher amperage rating). I'm nto convertin to this modern crap.
Ok, the largest amp rating in an old style 1G (what you're supposed to have) is 75 amps. These can be tough to find, 65 amps are easy though. There are alternator shops out there that can modify one or sell you one already modified to make 100 amps. Forcing an alternator to put out more than it was originally designed for usually makes it's useful life shorter though.
There exist "big body" 1G's. Physically larger than the regular ones and with slightly different wiring connections. They are usually rated at 100 amps though a few are 75 for some reason. Found on older Lincolns and some trucks with 460 engines, they can be bolted up with little trouble. They use the old style external regulator with the same connections, just two connectors on the alternator itself are for "spade" connectors instead of "rings". One's on my F100 basically because it does the job and so far has absolutely refused to die. It doesn't put out anything like the amps at idle a 3G can though.
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So what generation is the alternator I posted in the link?

D'oh! I really don't wanna have to mess with the wiring on my car. It's not that I don't have the knowledge, in fact I'm very electrically inclined, but I didn't wanna start splicing the factory harness.

Also, in that .doc file that Trick Pony posted, why are they fusing the positive cable? Also, I assume that adapter in that file just plugs into my stock harness(where do I get that adapter?)?

I'd still really like to go with a stock alternator so I don't have to splice my harness or deal with belt squeal(refer to Trick Pony's post).
That's purty! :winks ...but it's a 2G. It will bolt and wire right up with zero changes, but it STILL is whimpy! :laughlitt today's standards anyway.

You can find 2G alternators wired for 100 amp output on Ebay for a decent price or new ones from Summit for considerably more.

My question is why waste money on an inferior product? The swap is SO easy to do and when someone looks under the hood of a Foxbody and sees a 3G alternator they KNOW you are on top of the performance curve.... :worship

I paid about 200 shipped for a NEW 3G rated at 200amps and the deal included all the wiring. The 2G you are looking at puts out 70 amps at probably 1800RPM or so. Most all the 3G alternators put out 70 amps at IDLE! :eyepoppin

Now, if you drive a fair distance to work, and do not have a 'big' stereo system in your car, then go with 'purty.'

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I actually have no interest in whether it's chrome or not, that one just happens to be. I could really care less.

Also, where do I get the conversion harness at? And does it just plug into my existing harness? And lastly, why are they fusing the positive cable(I've never ever seen that done on a car, ever)? I really don't wanna do the 3G, cause obviously there's alignment problems as Trick Pony says it squeals, and that file he posted said it "should" not require any work to put a 3G in.

And lastly, you said Fox body, I hate Fox bodies. If someone wants to compare my 67 Coupe to a sh*tty Fox body car that everyone and their brother has, they're welcome to it, but I would never even put the nicest Foxbody car in the same league with the sh*ttiest of classic Stangs.

And lastly, when I'm lookin around on the net for alternators, how do I discern if it's a 1G, 2G, or 3G?
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For a classic, and I apologize as it was not noticed before, you might want to stick with the 2G. If it has the old mechanical regulator it is of low output and it is the 1G. The 2G simply had a had a few internal improvements and an electronic regulator. I'm not sure if the older, 1G, alternators are made any longer as they are interchangable.

The main reason cars migrated to 100amps is the requirements of EFI.

For a NA car 70 to 100amps is fine imho.

The large body alternators mentioned above, came on trucks and were dual belt. That's why it squeals with one.

Again, sorry to go on about this, but I assumed we were talking late model.

Stick with the Ford stuff!

:tongue :tongue
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So does the 2G still require the external regulator? And I'm to understand that the 2G will bolt right up to existing brackets and what not without problems?

Also, my car as it sits, as far as electronics goes, will only have an aftermarket CD player, electric fuel pump, and electric fan. I will eventually change it to an all MSD ignition though.

At this point I'm not sure I've made any progress from where I originally stood, I'm still quite confused on what to do. It seems that a 3G is not the way to go, but I haven't completely ruled it out yet until I know that something else will work fine with my car.

And I realize the differences listed between 1G, 2G, and 3G's, but how do I know what to order? They don't say it in product description or anything. So I can't look at alternators on Summit and know whether it's 1G, 2G, or 3G. Same goes for walking into a local parts store.
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If performance is your goal, 3G. :smoke:
You got any reasons to back that up? LOL. I guess I don't see the advantage of a 3G if I can get a 2G with 100 amps that WON'T cause squeal.

Anyone care to answer my questions in my previous post?
Quote--And lastly, you said Fox body, I hate Fox bodies. If someone wants to compare my 67 Coupe to a sh*tty Fox body car that everyone and their brother has, they're welcome to it, but I would never even put the nicest Foxbody car in the same league with the sh*ttiest of classic Stangs.---Quote

You seem to have a lot of issues that need to be resolved. Asking for info from guys who own these cars and then pissing them off with juvenile statements won't win you any brownie points. :sterb:
Hell, when everybody and their brother had lates 60s Mustangs, I drove Cougars! :laughlitt
Any help with those last couple posts of mine?
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