One wire alternator

[RivNut]

I’ve been reading about installing a 1-wire alternator. Apparently you run a fairly heavy gauge wire (14 ga.) directly from the alternator to the positive post on the battery - or to the horn relay where the positive cable connects. The 1-wire alternator has a built in voltage regulator eliminating the need for the external OE voltage regulator.  All is good up to this point except for the fact that you no longer have an AMP (idiot) light.  What does one do to retain the AMP light?  

[Bloo]

 

6 minutes ago, RivNut said:

What does one do to retain the AMP light?  

Not install a one wire alternator. The idiot light is another wire.

 

One wire alternators are a heavily compromised design intended for tractors where no one would care about their shortcomings. I don't consider internal regulated GM alternators of any sort an upgrade, but if you must, then buy a standard GM 10si or 12si internally regulated alternator instead of the "one wire alternator" and hook the idiot light wire up to the idiot light pin on the new alternator. Done. You'll have to extend the wire probably, it is at the regulator location now if you have an external regulator, and would need to reach the alternator. 

 

[telriv]

DO NOT USE 14 GAUGE.

10 GAUGE MINIMUM.

8 GAUGE BETTER.

 

Tom T.

Edited January 12 by telriv (see edit history)

[maok]

Often the generic 1 wire alternators, which a clone of the GM 10/12si do have a lamp (idiot light) terminal, usually labelled as L.

 

[RivNut]

1 hour ago, telriv said:

DO NOT USE 14 GAUGE.

10 GAUGE MINIMUM.

8 GAUGE BETTER.

 

Tom T.

I stand corrected. I started counting in the wrong direction.  I know better.  As a matter of fact if I go with the 100 amp alternator, I’ll probably need a 4 gauge wire. 

Edited January 12 by RivNut (see edit history)

[RivNut]

1 hour ago, Bloo said:

 

Not install a one wire alternator. The idiot light is another wire.

 

One wire alternators are a heavily compromised design intended for tractors where no one would care about their shortcomings. I don't consider internal regulated GM alternators of any sort an upgrade, but if you must, then buy a standard GM 10si or 12si internally regulated alternator instead of the "one wire alternator" and hook the idiot light wire up to the idiot light pin on the new alternator. Done. You'll have to extend the wire probably, it is at the regulator location now if you have an external regulator, and would need to reach the alternator. 

 

All of the 1-wire alternators I’ve looked at are replacements for passenger cars and light trucks.  Especially Camaros and Chevy pickup trucks with 350 SBC engines.  But they also list GM cars as well.  

[telriv]

Basically for the most part are ALL the same except for differences  in clocking.

 

Tom T.

Edited January 13 by telriv (see edit history)

[XframeFX]

 

2 hours ago, Bloo said:

One wire alternators are a heavily compromised design

Ed I'm on my 3rd alternator. Lesson learned, never again a junkyard and never again exchanging that junkyard unit for a rebuild, also junk.

 

As stated above, you want a proper 3-Wire alternator. I de-commissioned the AWG #10 and ran a AWG #8 for Alternator #2 which was a 61A 10SI. Now I'm running about 100A with a NEW Bosch 12SI. So a heavier wire for 8' would be better yet but entering "Cable" territory. Also, best I could do without purchasing a spool is  105°C marine wire.

 

This is what I purchased on Cdn Amazon, scroll down for my review:

https://www.amazon.ca/review/R12SJ7XNOR8F15/ref=pe_1086170_134824320_cm_rv_eml_rv0_rv

Review:

"This one (AL559N) has connector at 12:00. There is also AL533N with connector at 3:00 and AL547N for 9:00 position.
When swapping out for a double pulley, there was minimal threads. Swapping the spacer behind the fan produced more threads for full engagement of the Nut.
My vintage ride sees minimal summer only miles. So, would be FIVE STARS if this unit lasts forever.
Always choose a NEW 3-wire alternator and 12SI over the old 10SI unless a plastic fan does not appeal to you. No sketchy rebuilt units. Buy brand name new!"

 

 

 

Edited January 12 by XframeFX (see edit history)

[XframeFX]

I used a conventional Fan because the plastic Fan was close to rubbing with the thinner spacer ring. The plastic fan is more efficient. I don't think a plastic rub would be serious.

Again, this is with the double pulley.

[RivNut]

6 minutes ago, telriv said:

Basically for the most part are ALL the same except for differences clocking.

 

Tom T.

When I was working part time at Advance Auto, clocking alternators was a daily task.

[NTX5467]

Yes, many GM alternators differ only in how the rear case is clocked in relationship to the front case.  At the OEM/dealership level of things, what comes out of the box has to match what's on the car as is.  NO clocking allowed, lest the factory warranty be voided.  At the auto supply realm of things, "clocking allowed" so they only have to have ONE alternator to match many applications.

 

When I went to work in Chevy parts in late '76, I noticed that no new alternators or starters were cataloged, just "Reman" from Delco.  To look at the in the box, they looked as new as anything else I'd ever seen.  As I later learned, about the only part of the orig item they used was the case, with everything inside the case being new.  I do know they lasted as new, every time.  Haven't needed one since they went to their present multi-line products, though.

 

It is easy to replace brushes and diode trios in the GM alternators.  Which were the main things we sold for them.  Starting in 1988, with their then-new series of alternators, suddenly there were no rebuild parts in the Chevy parts books, just listings for "Reman Generators", yet we could buy rebuilt alternators in the aftermarket, so repair parts were available, just not from GM.  Key thing was that for a better customer feeling, they wanted us to replace the alternator, which had a warranty on it, rather than try to repair them (with sometimes sub-optimal results).  So the customer got a better value and piece of mind, as a result.  If GM's going to pay the repair bills, they can dictate what they sell.  BTAIM

 

Do you really need a 100A alternator for a car with no electric-heated back window?  Or are you anticipating a future EFI system or similar?

 

NTX5467

Edited January 13 by NTX5467 (see edit history)

[XframeFX]

6 hours ago, NTX5467 said:

Do you really need a 100A alternator for a car with no electric-heated back window?

Actually, 94 Amps. But my thoughts as well. 62 Amps would've been fine if the rebuilt 10SI didn't fail. But Auto Electric places are "scoffing" at the 10SI as being legacy as well. On the other hand, one Auto Electric place did not recommend converting to CS130 for reasons I cannot recall. Power Master with most of their offerings being 1-Wire have the bulk of their alternators being 12SI. They are reasonably priced and most default to chrome. But 1-Wire only, NG for me, stick with good ole Bosch.

So, I'm going with the flow, 12SI with more efficient cooling and is regulated to a max of 94 Amps. It went out-of-stock when I took delivery of mine. Back in-stock now I see (Right).

Also, consider Bosch AL533N. It is a 12SI Unit with 78 Amp capacity with a 3:00 connector. No stock anywhere though, special order only.

 

Bosch does offer one 62 Amp 10SI, very nice of them. Unlike WIX, they still support "old cars". It is AL530N (Left) and has the connector at the 3:00 position which would work as well for a passenger side installation although a little toasty with #1 exhaust below it. Much cheaper!

Again10SI, Cdn. Amazon:

https://www.amazon.ca/gp/product/B000BZIJ3E/ref=ox_sc_saved_title_1?smid=A3DWYIK6Y9EEQB&psc=1

Notice how there are more exposed rotor threads for a double pulley:

 

 

 

 

 

 

 

Edited January 13 by XframeFX (see edit history)

[XframeFX]

FYI: Underhood wire should be Automotive GXL or SXL wire. Easy to identify as they are marked with a 125°C rating. difficult to purchase just 8'. Even Auto Electric places say overkill, don't have it and say 85°C GPT Primary wire is plenty good - NOT!

If you must use GPT Primary wire (non underhood application), use brand name which is accompanied with SAE and temperature markings.

Wire Barn in NY someplace will sell in small baches.

Marine wire is "Tinned" and has a slightly better jacket with that 105°C marking.

[Frank DuVal]

7 hours ago, maok said:

Often the generic 1 wire alternators, which a clone of the GM 10/12si do have a lamp (idiot light) terminal, usually labelled as L.

Then it is not a one wire alternator, by definition!😉

 

The one wire alternator has a plastic plug to fill the hole where the tandem terminals are on a standard GM alternator. The internal regulator does not have the tandem terminals on it either.

 

❄️☃️🍾🎄

[arnulfo de l.a.]

21 hours ago, Bloo said:

 

Not install a one wire alternator. The idiot light is another wire.

 

One wire alternators are a heavily compromised design intended for tractors where no one would care about their shortcomings. I don't consider internal regulated GM alternators of any sort an upgrade, but if you must, then buy a standard GM 10si or 12si internally regulated alternator instead of the "one wire alternator" and hook the idiot light wire up to the idiot light pin on the new alternator. Done. You'll have to extend the wire probably, it is at the regulator location now if you have an external regulator, and would need to reach the alternator. 

 

Like the rest of the car, the electrical systems in our rivi were well built . The wire sizes used through out have plenty of circular mil area for the tasks at hand. The original alternators are superior to any big box parts store hands down regardless of the advertised amp capacity. You dont need 100 amps unless you are running some type of outrageous sound system. For a trouble free electrical system the entire system needs to be up to par. That does not mean all new wiring, connectors ,etc. It means no frayed wires, no loose connections, no oxidation at connection points, clean light sockets , accessible relay contact points cleaned. If all those potential issues are addressed you will have a perfectly functioning electrical system. ANY weak points in the system will tax ANY alternator,relays and voltage regulator. 

[XframeFX]

1 hour ago, arnulfo de l.a. said:

That does not mean all new wiring, connectors ,etc. It means no frayed wires, no loose connections, no oxidation at connection points, clean light sockets , accessible relay contact points cleaned. If all those potential issues are addressed you will have a perfectly functioning electrical system.

Not intending to deviate from Ed's original One-Wire post. But, yes. Electrical system is GMs Packard Electric. I re-wrapped my under-dash harness after adding a couple of circuits and online before/after images of re-wrapped harnesses for lessor cars. I discovered what quality the Riviera harness was. I still have the 60 year old wrap. Quality material and applied by a Craftsman.

 

However, the #10 charge wire from the inner fender well to the alternator was hard and crispy. The reason why I replaced through to the horn relay junction post rather than splice. Also, re-crimped series-56 female connectors for the alternators' idiot light and compensation lead with layers of heat shrink for strain relief. Actually they should be replaced too. Or, go to 1-Wire Alternator- LOL😊!