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[C2] One Wire vs Three Wire Alternators.

 
Old 09-11-2018, 07:35 PM
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woodsdesign
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Default One Wire vs Three Wire Alternators.

I have a one wire alternator but I was made aware of it's disadvantages in another post "Bubba at his finest" Since I didn't want to steel that thread I am starting a new one.
My car has a lot of modifications like Holly HP fuel injection, Vintage Air and Cebie headlights that may be affected by voltage. I have not had any issues with my one wire (100 amp) alternator but after reading an article by Mad Electrical (thank you GEM "62 ) I realized that it is probably not the best choice. This is mainly because of the voltage sensing wire. If I can get better performance with a three wire set up then I am willing to admit my mistake and convert.
So, here are my questions:
1) Is it an easy fix to convert to three wire if I purchase the Mad Electric conversion harness. ( What is involved considering I have converted to a one wire set up)
2) Is it worth the effort to convert. ( will I see an improvement in performance of my add ons )
3) Has anyone performed this mod with the Mad Electrical wire harness conversion? Experience is always the best lesson.

Thanks in advance for your help.
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Old 09-11-2018, 08:13 PM
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Originally Posted by woodsdesign View Post
I have a one wire alternator but I was made aware of it's disadvantages in another post "Bubba at his finest" Since I didn't want to steel that thread I am starting a new one.
My car has a lot of modifications like Holly HP fuel injection, Vintage Air and Cebie headlights that may be affected by voltage. I have not had any issues with my one wire (100 amp) alternator but after reading an article by Mad Electrical (thank you GEM "62 ) I realized that it is probably not the best choice. This is mainly because of the voltage sensing wire. If I can get better performance with a three wire set up then I am willing to admit my mistake and convert.
So, here are my questions:
1) Is it an easy fix to convert to three wire if I purchase the Mad Electric conversion harness. ( What is involved considering I have converted to a one wire set up)
2) Is it worth the effort to convert. ( will I see an improvement in performance of my add ons )
3) Has anyone performed this mod with the Mad Electrical wire harness conversion? Experience is always the best lesson.

Thanks in advance for your help.
I am in exactly the same situation and read the Mad Electrical also. Not sure I agree with all of it but it does make sense. I was told, although I am not sure that you would have to open up the alternator and change the voltage regulator. I was hoping to just pop the rubber plug out and change the wiring. Maybe someone else that knows more than me on electrical can chime it. I have a low option car and ran the electrical fan relay lead directly off of the alternator so the rest of the car is oem for now. Good Luck

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Old 09-11-2018, 09:11 PM
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Personally, I think this is much ado about nothing. A one-wire typically needs to hit about 1500 rpm to start charging. You can see this with a voltmeter. If the car is warm and you turn the key and start it, you will see about 12.8v meaning the alternator is not supporting the battery. Rev the engine and the voltage kicks up to about 14.5v meaning the alternator is charging the battery and supporting the electrical load. If the car is cold and you have a choke, when you start it you push the accelerator pedal to the floor once, release it, and turn the key. The engine starts and the choke fast idle causes it to idle high enough to trigger the alternator and all is good. Much ado about nothing.
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Old 09-11-2018, 10:03 PM
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Since you are familiar with MADD you know that the original design of 60's GM cars using the 10DN Delcotron featured a "central bus" which is a horn relay lug from which the system load is distributed and from which the voltage regulator senses system voltage. This is a fine system for the original auto, but for a resto-mod with all manner of additional system load what is most important is fusing and proper wire size. A 1 wire alternator is fine for this purpose - its output capacity increase mitigates any advantage in its regulator seeing system voltage from a central location.

Dan
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Old 09-11-2018, 10:10 PM
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Originally Posted by Vette5311 View Post
I am in exactly the same situation and read the Mad Electrical also. Not sure I agree with all of it but it does make sense. I was told, although I am not sure that you would have to open up the alternator and change the voltage regulator. I was hoping to just pop the rubber plug out and change the wiring. Maybe someone else that knows more than me on electrical can chime it. I have a low option car and ran the electrical fan relay lead directly off of the alternator so the rest of the car is oem for now. Good Luck
Yes, just pop the plug and wire according to Mad Electric. You can get a plug at your parts store
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Old 09-12-2018, 08:02 PM
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Originally Posted by GCD1962 View Post
Yes, just pop the plug and wire according to Mad Electric. You can get a plug at your parts store
So glad to hear that. I ordered the wire kit and will change it later when I put new wiring harness in. Thanks again.
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Old 09-12-2018, 09:42 PM
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But the voltage regulator is where you hide the headlight relays and the 1-wire alternator allows you to do this.


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Old 09-12-2018, 09:44 PM
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You can still do that. The three wire has an internal regulator.
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Old 09-13-2018, 11:39 AM
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Default Great Idea,...........

Originally Posted by toddalin View Post
But the voltage regulator is where you hide the headlight relays and the 1-wire alternator allows you to do this.

I plan to copy this for when I do headlight relays, glad I didn't throw it away, I almost did. This is a really good idea, Thx again.

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Old 09-13-2018, 02:04 PM
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Originally Posted by Vette5311 View Post
I plan to copy this for when I do headlight relays, glad I didn't throw it away, I almost did. This is a really good idea, Thx again.




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