1 Wire Alternator with American Auto Wire Kit 1972

[Aztec.A]

Howdy everyone,

I have a 1972 C20 Custom. The wiring is junk, the Ammeter is fried and it's time to get to work.

I ordered the Classic Update kit. It requires the use of a special connector/ harness to run the Externally regulated set up.

The kit is set up for a 1 wire alternator. It clearly states you can not use the factory Ammeter since it is not an original harness and is set up to handle higher voltag/current.

My question is who has used this kit?

Who has done a one wire conversion?

What alternator is used?

What Voltmeter was substituted?

Please help!!!!!!!!

Thanks y'all!

Dave

[dfwright]

Dave, I haven't done the alternator yet, but I went to pick-n-pull and got a volt-meter out of a '79 truck. These will bolt right in to the spot where the ammeter is. I took it apart an put my ammeter cover over the voltmeter guage so it would look normal in the dash. If you search on the board, there's several threads about the volt meter conversion.

[VetteVet]

Originally Posted by Aztec.A

Howdy everyone,

I have a 1972 C20 Custom. The wiring is junk, the Ammeter is fried and it's time to get to work.
If the wiring is junk then there's not much you can do except replace it with a new harness. The ammeter (charging gauge ) has two wires and two small fuses that control it. You might just have a blown fuse or a bad wire running to it keeping it from working.


I ordered the Classic Update kit. It requires the use of a special connector/ harness to run the Externally regulated set up.

This is misleading in that the one-wire alternator has an internal regulator and it does not require anything special to make it work. If you were converting to a regular three wire alternator, which you should, then you would need the harness or you could just make your own. Or you could use my method and it would be very easy to get rid of the external regulator, and it's wiring, and you'd have a much better setup.

The kit is set up for a 1 wire alternator. It clearly states you can not use the factory Ammeter since it is not an original harness and is set up to handle higher voltag/current.

Being setup for a one-wire alternator only means that the harness does not have the conversion wires included. A one-wire alternator does not require any special wiring. If you know how to wire the harness, the ammeter will work just fine if the gauge itself is OK.

The ammeter is just a gauge which shows that the alternator is charging, it does not have large currents or voltages running through it. The older trucks pre-63 I believe, did run all the current through them and were limited to 60 amps but that doesn't apply to yours.

My question is who has used this kit?

Who has done a one wire conversion?

What alternator is used?

What Voltmeter was substituted?

Please help!!!!!!!!

Thanks y'all!

Dave

Type "alternator conversion" in the search box near the PM message notification at the top of this page and you will get lots of information.


http://67-72chevytrucks.com/vboard/s...d.php?t=417872


here is an example--------

[Aztec.A]

dfwright, I'll see if the local yards have one. I can't seem to find anything earlier than 1985 in most yards.

VetteVet, I have a brand new American Autowire Classoc update kit. I'm trying to figure out what it needs. Maybe I'm not reading this right or overcomplicaring something.

Attached is page from the kit and the set up I have.






Posted via Mobile Device

[VetteVet]

[QUOTE=
VetteVet, I have a brand new American Autowire Classoc update kit. I'm trying to figure out what it needs. Maybe I'm not reading this right or overcomplicaring something.

Attached is page from the kit and the set up I have.

[/QUOTE]

What you have is the stock setup for the 67 to 72 charging systems. The external regulator and the alternator and the harness will all be deleted with the classic update system. This is actually what should happen with our trucks for better performance when we add the modern accessories such as cooling fans, air bags, high amp stereos etc.

Without seeing their wiring diagram I can't tell what wiring circuits they are using in detail, but if they have designed it for a one-wire alternator, they will leave out the wiring needed if you decide to go to a three wire later on. I would think that more than likely they will include the wires but will have them isolated since you won't be using them. Although you should. after reading paragraph 2 I see that they supply the wiring for the three wire alternators as well, and state that some adapters may be needed.

I assume that you are contemplating an SI type 0ne-wire alternator which is probably what the kit is designed for. If you go to the CS style you will need an adapter for the newer alternator with a built in resistor.

In paragraph three they explain why the ammeter will no longer work, and they are correct if you wire the system the way they explain. Which is to run the 8 gauge alternator output wire directly to the battery, via the starter cable, at the starter, which bypasses the ammeter wiring. They claim that this is the most optimal way to charge the battery.

This is they way that the newer trucks starting with 1975 have wired their alternators but they also take the power outputs off the starter cable terminal and they have gone to the voltmeter and eliminated the charging gauge(ammeter).

All you need to do is to run the 8 gauge alternator output wire to the main junction that you have in the harness now on your truck, and the battery will charge just fine. Not only that but if your ammeter is OK and the wiring and fuses are good it will work just fine as well. This has been proven over and over by others on the forum.

It would be helpful to know how they plan to supply power to the rest of the truck.

I hesitate to get too deep into the wiring without knowing how they are routing it and also to avoid confusing you.

Here is the way the stock wiring runs from the alternator and how the ammeter wires are routed. I hope you can follow it. All the red wires go into the main junction I mentioned above. The 18 gauge black and black/white wires are the ammeter wires with the four amp fuses inline.



This is the way the updated,internally regulated, 12 SI three wire alternator would be routed.



The one-wire alternator would be routed the same, except that you wouldn't have the two small wires that plug into the alternator body. With this circuit the ammeter would still work. If you run the large red wire to the starter as they plan to do, it bypasses the ammeter wires and the ammeter would not work.

[Aztec.A]

http://www.americanautowire.com/shop/classic-update-series/complete-wiring-kit-1969-72-truck

Above is the link to the kit info page. At the bottom it gives a section for instructions and breaks down the harness by sector.

I don't think I have the right alternator to work with this kit. Correct me if I'm wrong. I'm a noob to some of these older electrical systems.

I just need the truck to start so I can move it in and out of my shop for business.

Thanks for pointing out some good things to consider VetteVet. Take a gander at the wiring diagrams in the link and tell me what you think.
Posted via Mobile Device

[notsolo]

I have the AAW classic update, its a great choice. You will need the crimping tool for the ends and yes an alternator that they recommend. ( I changed over to a serpentine belt setup, newer alt.) Takes some time but you will have a better understanding of the wiring in the end. There instructions are ok, could be better.

[davepl]

Are they just blowing electrical smoke there about the ammeters becoming a safety hazard because alternators used to only by 50-60A and now they're over 100A?

It's not like the current runs through the ammeter. I've pegged it on my old 2+2 (originally 37A now 100+) and never thought much about the gauge being pegged because it's just reporting a voltage differential - it's not a current flow ammeter.

So, are they right? Or just 'splaining away their loss of functionality for 1-wire setup?

[notsolo]

There is a separate pigtail off the fuse box 8-10" long with a connector for accessories. 6 wires total, Red wire looks to be 10 gauge. ( Sorry crappy photo,) under the pdf 510091 dash kit. Diagram is deceiving shows a single strand. I missed the ammeter warning. Hopefully won't need it, I am going to try the Intellitronics digital gauges. I have not looked into wiring there bare wires into the dash pigtail yet.