One wire alternator

[xs-cash]

I have a 72 Chevy truck with 350 still has the old alternator with external voltage regulator, what’s involved with changing it Tina one wire ? Do I change or modify the original wiring?

[jgrote]

You're amp meter won't work, but most of them don't anyway. There are several videos out there on how to install a volt meter in it's place. A 1 wire is exactly that; 1 wire. All you need to do is run a wire from the back of the alternator to the battery. You need to size the wire correctly based on the output of the alternator to the positive side of the battery. However, it's not much more work to wire up an internally regulated (3 wire) alternator. I've had a 1 wire on a couple of other cars before with no issue, but for some reason it seems frowned upon.

[72SB]

my 72 was converted to 1 wire by PO....I intend to use a 3 wire and restore wiring. I prefer 3 wire.

Use a solid state VR. Tuff Stuff (Amazon). Especially if you have a Pertronix kit in dizzy

Never understood why people want to convert to a 1 wire alt on 3 wire set ups

[xr4tic]

I put a 1-wire Jegs alternator on mine and haven't had any issues so far:
https://www.jegs.com/i/JEGS/555/10144/10002/-1

The downside to a 1-wire is that it has to see a certain RPM to self-excite before it starts charging. Jegs says theirs requires a lower RPM, but I find that it takes 10-15 seconds before voltage will go up from 12V to 14V to show it's charging.

The upside is less wiring/cleaner engine bay, but you should remove the old wiring as well.

I don't know if it will bolt into the stock bracket either, I moved mine to the passenger side so it's closer to the battery and ran 2AWG cable. I still haven't cleaned up the original wiring, I just cut the ends off, wrapped it in electrical tape, and tucked it away for now.

[Jason Banks]

You would probably be happy converting to a 10SI or 12SI type alternator that is internally regulated. The wiring to convert is super easy, or you can get an adapter kit.

https://www.summitracing.com/parts/aww-27555

One plug goes on the harness that goes to the regulator and the other to convert the plug on the alternator.

Scroll down this page for some part numbers for the different versions...
http://www.madelectrical.com/electri...elcoremy.shtml

If you shop around you can usually find a new/reman 10SI for around $60

[MARKDTN]

I would also vote 3 wire internal regulated 10 or 12si. Very easy swap. You basically bypass the regulator and swap the plug at the alternator. Up to 63A I believe can use stock wiring and ammeter. If you go bigger you should get rid of the ammeter and upgrade some wiring.

The reason 1 -wires are frowned upon is that they do not sense system voltage. They work great for a piece of equipment that turns on and runs at that load all day. If you have fans kicking on and off and a/c and radio-etc. they do not do as well at maintaining a consistent charge.

http://www.madelectrical.com/electri...reewire3.shtml

[xr4tic]

Originally Posted by MARKDTN

http://www.madelectrical.com/electri...reewire3.shtml

Oof. They compare a 1-wire alternator using a worst case scenario (large voltage drop in the charging wire) to a 3-wire alternator using a best case scenario ("when this system is wired effectively")

Sounds like someone trying to sell you something. Oh wait, they are.

I do agree that a 3-wire is great if you want to maintain the factory harness and not do any other upgrades.

If you're planning on wiring upgrades, either alternator will be fine.

[LNP]

For me the big reason for switching to a one wire altenator was low engine rpm full charging. Most alts dont charge well at low rpm. Yes one wire is easy install, stepping up in amps output is easier as well, these altenators are internally regulated so you are not loosing a voltage regulator either. A volt gauge can be easily added by just tapping into a key on positive wire under the dash or out of the fuse box. Here is a couple technical articles, one from Power Master and one from Tuff Stuff.

http://powermastermotorsports.com/te...Alternator.pdf

https://www.tuffstuffperformance.com...structions.pdf


Here is a article that explains the ins and outs to one wire alt switching completely in detail

https://www.streetmusclemag.com/tech...er-to-hook-up/

[xs-cash]

Thanx for the reply’s guys !