The Truth About One Wire Altenators.

[Lakota]

Keep this in mind:

The guys from GM and Delco-Remy were not idiots, they new what they were doing when they designed their altenator. There are three wires on an altenator for a reason.

First off, electricity cannot be created, nor distroyed. But it can be altered. It must come from one of the five sources, (heat, light, friction, magnetism or chemical reaction). Altenators work on magnetism, but they must have a voltage source to create the magnetism, (battery). This is as far as I'll go on this, otherwise I'll type for two days and you'll end up with a degree in Electronic Engineering.

In laymans terms, let me explain why a three wire altenator is superior to a one wire altenator:

A standard internally regulated altenator has three wires coming out of it. One is the large gauge red wire that goes directly to the battery, (charge wire). The second is the smaller gauge colored wire, (pin 2-voltage sensor). The third is an equal size wire, (pin 3-sometimes used for indicators or gauges). It's pin 2 of the two wire plug-in that is important here. Pin 2 is connected to the fuse panel, and as you know everything is connected to the fuse panel. Pin 2 is the feed wire for the internal magnetic field that generates electricity. Pin 2 is also the voltage sensor for the altenator. It reads or measures the voltage at the fuse panel. If it's low (below 12V), it triggers the altenator into a charge mode. When the voltage at the fuse panel is brought up to normal (13.6V-14V), the sensor tells it to free-wheel. In this manner, the fuse panel always has enough voltage to power all the electrical devices at full voltage.

The one wire altenator only has one large gauge red wire from the altenator to the battery. So how does it control the altenator? It doesn't!!!
A small internal wire or diode is used as a jumper between the charge wire and pin 2. pin 2 is now reading battery voltage instead of actual voltage at the fuse panel. When the battery gets low, pin 2 triggers it into charge mode. As soon as pin 2 reads the charging voltage it triggers it into free-wheel mode. When the battery voltage falls below 10 volts, then it will stay on long enough to charge at 12 volts and then shut off. Eventually, the battery gets charged. Meanwhile, back at the fuse panel, voltage has been fluctuating between 9.5 and 10.5 volts.

So what does this all boil down to?

With a one wire system and low voltage at the fuse panel, your new expensive CD system sounds like crap, your lights are constantly dim, and that new Super Duper Spiffy ignition system with the 35,000 volt output is only giving out 18,000 volts to the sparks. You're right back to a stock distributor (can you say fouled plugs?). Oh yeah, need I go into how it affects a computer controlled TBI (can you say poor MPG?)???

In short, keep the three wire system. Dress it up with a brightly colored loom. And put your hard earned money elsewhere.

 

[WIZEGUY]

Not to take issue with you, but I have to disagree.
Keep in mind I don't have any type of electronics degree, nor can I talk the electronic lingo. But the only thing I can offer up here is my own personal experience, through my common sense approach to building.
.
My Chevelle had the three wire alt. After adding the MSD, elec. fuel pumps, Spal fans, aftermarket gauges, etc. the car constantly ran rich, poor voltage, etc. around 11.8 to 12.5 volts in charge mode. After doing a amp draw calculation, I determined my entire electronics system was needing around 105 amps to run everything efficiently.

I wanted to "soup up" my 3 wire as it was only putting out around 70 amps, and was told by a few alt. shops they could only take it to about 95 amps. Due to not being able to modifiy the components in the stock type alt. to the level I needed.
I put in a call to PowerMaster and ordered one of their one wire jobs.
I hooked it up with no other changes. The car now runs cleaner, smoother, lights burn brighter, and I have a constant 13 or so volts at any point.
I have installed these alt. before on customers cars at there request, but have never had the need for one until that point.

SIDE BAR: After reading this thread I checked my car this evening at the fuse panel and I had 12.8 volts. Not to prove you wrong, but you got me concerned about the efficiency of my system.

My understanding is that the cars system runs off the battery and the alt. job is to be there to replenish the battery.
Isn't that what makes the car stereo, hot ignition, etc. not work properly, more amp draw than the alt. can supply back to the battery? Which is what pulls the battery down to begin with, again, more amp draw than the alt. can supply?

I've been wiring cars with this in mind for years and have never had a problem. I always use correct gauge wire, good connections, relays instead of running off switches, etc.

Again, I don't have any type of formal education when it comes to wiring. I just know what I've figured out and most important, what my own eyes and hands have seen and done.

Thanks for your post Lakota.


Tracy

 

[Lakota]

I graduated Wentworth Inst of Tech...I do have a degree.

I sat here staring at the screen for twenty minutes trying to figure out where to begin...So I won't

This post was aimed at the guys that have been led to believe that the one wire system is "cool". It isn't. If you've got a "trailer queen" and all you do is drive on and off a trailer and in and out of a show, then a one wire system is ok. We're talking rat rods here. They're driven daily. A simple HEI or equivalent dist, simple radiator fan, possibly a computer and a TBI, and an electric fuel pump. Yes, the battery powers everything and the altenator rejuvenates the battery. Any 55 amp altenator will handle this load with ease. I've seen more guys go to the one wire and boast about it, only to quietly return to the 3 wire system. The one wire system is a trade-off, appearance for performance.
If you're happy with your system, great. And I'll leave it at that.

 

[RRR Mod]

Thanks!

Thanks for your comments guys. Like I say... rodders are very spirited folks (I said folks) and will sometimes disagree. Since I have openly admitted I don't have a clue here I will take these comments at face value. I run 1-wires but the only accessory I ever run is a stereo. Now move over suckers, I'm headed for the passin' lane!!!

Rat Rod Mod

 

[chop509]

I've used both, but now I'm running a generator !

Jeff

 

[Lakota]

OK,OK...I admit it. I looked into a one wire alt also. I mean I really looked into it. I talked with guys on other sites and alt repair shop guys. I even tore a couple apart just to see how they were wired and operated.
I showed this post to my wife and she got all over me about the wording in my post. She said it sounded like I was being self-rightious and uppity, and made me promise to play nice. Then after a good thrashing, she made me stand in the corner. Wanna see my cool bruises???

 

[Tripper]

Me too!

I've used both, but now I'm running a generator !

Jeff

I run one sometimes too... ; - >

 

[chop509]

I run one sometimes too... ; - >

Yeah, but with those it's hard to find a place to mount 'em.

Jeff

 

[WIZEGUY]

Let me take these items one at a time.
First: I didn't think you where using an uppity attitude what so ever. I don't think anyone here could ever draw that conclusion from reading any post you have wrote. I enjoy reading your post.
I just read this post and saw some things that didn't add up, verses what I've saw what works.

Second: While I know you were not aiming this comment toward me, my car is not a trailer queen. I drive it to every car event I've ever went to. That includes 400 plus miles one way. I've actually past trailers with rat rods on them going to the same show. ( They must have been using a 55 amp 3 wire alt......lol)

Third: What does it matter if it's a rat rod or a V8 Vega? 12 volts is 12 volts. Either you drive it and everything works properly or it doesn't.

Fourth: How can you have knowledge and not pass it on? I'm not saying I'm right and you're wrong. I'm just saying what I've seen and made work.
Why won't you explain to me and others on this TECH forum why my system won't work. I'm opening to learning any day. Electrical is my weak point.
Share the knowledge. It can be explained in simple terms.
(BTW, I checked my system again today with another meter at the fuse box...12.9 to 13 volts). What's not working right here?

Finally: I'm not trying to pick a web fight nor trying to make myself look smarter. I'm not trying to hurt anyones feelings either.
I'm just wanting people on these post to back up their statements.

You made a statement that a one wire alt. won't power anything other than a small amp draw system.
I'm using a one wire, high amp alt., with a demanding amp draw system. I drive this car on long runs, day or night. I've never had a problem.
Please...tell me why my system isn't working.
If you can make me and my charging system understand why it can't work, maybe it will quit that nonsense.......lol

I'm going to paste in info on how one wire alt. work. These are NOT my words. They are from Powermaster.


Powermaster early style Delco alternators will work either way - as a one wire or OEM style. The main difference between a one wire and an OEM is the method used to energize or turn on the alternator. An alternator using the OEM style is turned on with the ignition switch. The one wire design is energized with a special sensing circuit built into the internal voltage regulator. This circuit senses the rotation of the alternator’s rotor. The rotor must turn at sufficient speed to trip the circuit, starting the charging process. This turn-on speed is affected by several things and is typically higher with certain high amperage alternators. Once this circuit is tripped, the alternator will charge at all speeds, even very low ones, until the alternator’s rotor comes to a complete stop. At that point, the circuit will shut off and wait for the process to be repeated. What this means for the consumer is that in some applications the engine must be revved to 1200 or 1400 RPMs to turn the one wire alternator on. If the wiring harness is available and this characteristic is annoying, then Powermaster alternators can be plugged in like the stock unit and operated with the ignition switch.


Tracy

 

[Lakota]

I posted. I based my information on fact, knowledge of electronic theory, bulletins from GM and Delco-Remy, verbal communications with altenator repair shops, physical hands on observation, and numerous posts on other sites about the subject.

You replied. Based on your experience, with your altenator, in your Chevelle.

Others replied. In a like manner

I again replied. Only I left the wit out of it.

RRR replied. He was letting us both know that with a little provocation this thread could turn into a full blown arguement.

I replied. With full wit, hoping to squash any ideas of provocation. Didn't work!

When I returned to the site after dinner and some leisure time I found this sugar coated invitation to a debate based on advertising hype, followed by provocations (Still waiting for information to be passed on...Still waiting).

Here's your information:
In the mfg own words.
The rotor must turn at sufficient speed to trip the circuit, starting the charging process. This turn-on speed is affected by several things and is typically higher with certain high amperage alternators. Once this circuit is tripped, the alternator will charge at all speeds, even very low ones, until the alternator’s rotor comes to a complete stop. At that point, the circuit will shut off and wait for the process to be repeated. What this means for the consumer is...What this means is that you'll sit in your driveway revving your engine until the altenator decides to start charging, and it won't stop charging until you shut off your engine. The battery runs the gamit between under charged and over charged.
If the wiring harness is available and this characteristic is annoying, then Powermaster alternators can be plugged in like the stock unit and operated with the ignition switch.
If the altenator is set up as a one wire, then pin 2 is connected to the output lug for a sensor voltage. Any voltage from the fuse panel would have no affect. It will continue to work as a one wire.

 

[Inked Monkey]

God d*****! Please dont leave Lakota. I've learned A LOT from your electrical posts. Please come back!!!!

 

[SmallBlock Jimmy]

Ive "made" most of my regular alternators into "1 wire" alternators long before they actually came out with them. Almost 20 years Ive been doing this and I havent noticed any problems but I'll check my voltages at the fuse panel when I get a chance.

 

[RRR Mod]

Open again!

Ok, open again... let's keep it lite!
RR Mod

 

[donsrods]

Thank you for reopening this thread Bob. I've reread it twice, and can't see that it was anything but a normal, respectful point and counterpoint discussion. Not sure why some feathers got ruffled, but there was nothing confrontational about the responses at all.

Anyway, that being said, I have run about 4 one wire alternators, and have two more cars not running yet that have them. I used to sell them when I was in the Marine business, and had them on two of my boats. I like them because of the ease of installation, and have had no problems beyond what one would expect out of any alternator. The one on my Jeep/5.0 swap is in it's 4th or 5th year, and still works great.

I am no expert, but my own experiences have been good, so I will continue to use them.

Don

 

[WIZEGUY]

Keep in mind, I do not have an elec. degree. But I have been building cars for a living for over 12 years.

On the one wire alt. problems, that Lakota mentioned, there are some truths to what he said. If you "loop" the wire on stock alt. and do nothing more to modify your wiring system, you MAY incounter voltage drop problems.
These problems come only when using a stock, low amp factory alt and a unaltered wiring system.
He made a general statement that ALL one wires are bad. I'm going to cover
aftermarket, high amp, alt that do work properly when installed correctly.

He kept speaking of voltage drop at the fuse panel and the alt only topping off the battery and then shutting off, only to leave the fuse panel hanging with around 10 volts.

First off, when custom wiring a car, you don't rely on a small wire to supply current to your fuse panel.
If you are not getting the proper amount of voltage to ANYWHERE in the system, put it there.
You can put the proper amount of voltage, but most importantly amperage, to any point in your system from the battery. All you have to do is use the right gauge wire.

From the after market alt., that sends voltage through a VOLTAGE REGULATOR, a large gauge wire is connected to the battery.
From the battery connection, another large gauge wire is sent to the system. The alt. senses voltage and amp draw at this point. If the system, which includes the battery, needs power from the alt. it will give it.
But if your alt doesn't have a voltage regulator, you may have problems...lol
What's so hard to understand about this?
But of course I say this only to people who have used quality after market alt and wired their systems for them, and see that they work.

The reason I went to an aftermarket alt is because I couldn't get the required amperage from a factory Delco style alt.
I had a option to use the one or three wire. I chose the one.
I do not have to sit in my driveway and keep revving the engine until the alt. decides to charge.
It takes 1200 rpm, one time, to do it. My battery does not run the gamit between under and over charged. I guess my voltage regulator must be working....lol
At anytime or at any point, be it when I first start the car or have been driving for 400 miles, my system has the proper amount of voltage. Not over or under.
The reason I know this is because I test everything on my cars after they are finished.
If you will do this you can give detailed information to doubters when questioned. It doesn't matter if it's the charging system, carb or whatever.

It looks like there are others on here who are having success running one wire alt. Do you think it's luck, or do you think it's the fact they done their homework?


Tracy

 

[Onequick26]

Ok,im about to get ready to wire my car in a few weeks and i am going to use a 1 wire alt.Now here is my qustion.

I have been told that I have to use a in-line diode so the system dose not back feed and cause a diesel effect when i shut off my car. so do I have to do this with all alts or just when converting a 3 to a 1 wire ?

 

[WIZEGUY]

26...which way are you going to go. looped stock alt. or aftermarket?

 

[Onequick26]

aftermarket.

 

[WIZEGUY]

I would run one from Powermaster. I've seen and used some of the no names, like the ones Summit carry, and they are nothing more than stock, Jap crap modified units.
The Powermasters are true high amp units. If the 1200 rpm turn on feature bothers you, you can install the kit to supply the 12 volts to the alt. when the car is started.
It's never bothered me because my Chebby idles at 1100 rpm. I don't have to rev. mine to go the extra 100 rpm, just got to lay my big toe on the throttle.

But to answer your question, no, I didn't install a diode. I've not had any problems like you asked about.

But like I say, never think you have seen it all.

If you read my last post on how I wired up mine you shouldn't have any problems.
But remember, don't take my word for it, test everything after you are done.

 

[Groucho]

Agree. I've used my own "jumped" one-wire deals on everything from daily drivers with big stereos to 10 second drag cars with MSD's, elec fans, water, and fuel pumps, for YEARS with great results

Not to take issue with you, but I have to disagree.
Keep in mind I don't have any type of electronics degree, nor can I talk the electronic lingo. But the only thing I can offer up here is my own personal experience, through my common sense approach to building.
.
My Chevelle had the three wire alt. After adding the MSD, elec. fuel pumps, Spal fans, aftermarket gauges, etc. the car constantly ran rich, poor voltage, etc. around 11.8 to 12.5 volts in charge mode. After doing a amp draw calculation, I determined my entire electronics system was needing around 105 amps to run everything efficiently.

I wanted to "soup up" my 3 wire as it was only putting out around 70 amps, and was told by a few alt. shops they could only take it to about 95 amps. Due to not being able to modifiy the components in the stock type alt. to the level I needed.
I put in a call to PowerMaster and ordered one of their one wire jobs.
I hooked it up with no other changes. The car now runs cleaner, smoother, lights burn brighter, and I have a constant 13 or so volts at any point.
I have installed these alt. before on customers cars at there request, but have never had the need for one until that point.

SIDE BAR: After reading this thread I checked my car this evening at the fuse panel and I had 12.8 volts. Not to prove you wrong, but you got me concerned about the efficiency of my system.

My understanding is that the cars system runs off the battery and the alt. job is to be there to replenish the battery.
Isn't that what makes the car stereo, hot ignition, etc. not work properly, more amp draw than the alt. can supply back to the battery? Which is what pulls the battery down to begin with, again, more amp draw than the alt. can supply?

I've been wiring cars with this in mind for years and have never had a problem. I always use correct gauge wire, good connections, relays instead of running off switches, etc.

Again, I don't have any type of formal education when it comes to wiring. I just know what I've figured out and most important, what my own eyes and hands have seen and done.

Thanks for your post Lakota.


Tracy