Chrome Alternator..1 or 3 wire... Regulator?
Thread Starter
Pro
Joined: Oct 2007
Posts: 654
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From: Crusing the roads of the great USA
Chrome Alternator..1 or 3 wire... Regulator?
Thanks to my previous thread and great answers i was able to purchase the alternator set up for my 70 vette and will do away with the header mount system. So... while i'm at it why not buy a nice chrome alternator..and there lies the new problem. I have a 70 with a drivers side alternator with numerous wires coming out the back. While looking i notice that they are 1 wire hook up. and internal or external regulator. To be honest i dont know if i have an internal or external regulator. Must i buy an alternator with all the wires in the back for my factory dash gauge to keep working? How can i tell if i have an external or internal regulator and lastly what amps should i buy? Radio is stock, no high power amps to worry about. I think the only electrical change over stock is an msd set up and a 3hp mini starter.... Thank You!
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
One-wire alternators are for boats and tractors. Read the MAD Electric site for a very good description of the pros and cons of various systems...and keep in mind where a C3 battery is mounted.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
If a car doesn't run right with one there is a problem with the car somewhere else.
My 1 wire Summit 100 amp made my car run better and I have 0 problems.
The mad site just wants you to buy some more electric parts from them, a 1 wire wouldn't need anything so they don't make money off them.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
TimH..What did you do about the GEN light?
IMHO, stick with the 3 wire, get it in chrome if that thrills you. There are reasons that NO ONE in the modern world runs a 1 wire alternator. Yes they will work and if your lucky you won't have any trouble with it. But, if your not electrically savvy it can seriously run you around the yard some.
IMHO, stick with the 3 wire, get it in chrome if that thrills you. There are reasons that NO ONE in the modern world runs a 1 wire alternator. Yes they will work and if your lucky you won't have any trouble with it. But, if your not electrically savvy it can seriously run you around the yard some.
Burning Brakes
Joined: May 2007
Posts: 1,150
Likes: 14
From: LaMoille Illinois
TimH..What did you do about the GEN light?
IMHO, stick with the 3 wire, get it in chrome if that thrills you. There are reasons that NO ONE in the modern world runs a 1 wire alternator. Yes they will work and if your lucky you won't have any trouble with it. But, if your not electrically savvy it can seriously run you around the yard some.
IMHO, stick with the 3 wire, get it in chrome if that thrills you. There are reasons that NO ONE in the modern world runs a 1 wire alternator. Yes they will work and if your lucky you won't have any trouble with it. But, if your not electrically savvy it can seriously run you around the yard some.
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Thanks to my previous thread and great answers i was able to purchase the alternator set up for my 70 vette and will do away with the header mount system. So... while i'm at it why not buy a nice chrome alternator..and there lies the new problem. I have a 70 with a drivers side alternator with numerous wires coming out the back. While looking i notice that they are 1 wire hook up. and internal or external regulator. To be honest i dont know if i have an internal or external regulator. Must i buy an alternator with all the wires in the back for my factory dash gauge to keep working? How can i tell if i have an external or internal regulator and lastly what amps should i buy? Radio is stock, no high power amps to worry about. I think the only electrical change over stock is an msd set up and a 3hp mini starter.... Thank You!
as for the guages, I am 99 percent sure the ammeter taps into the charging circuit off the main engine harness leading down to the starter. Id have to go home to pull my witing diagrams buy the short answer would be no. the long answer would be you could but you would have to do some wiring mods to tap into the charging system outside of the stock harness.
Read the MaD paper linked here it is pretty good, and Ive done a lot of wiring on old cars/ trucks. If you dont have a need/ desire to rewire the car, and the harneses are in good shape, go with the standard 3 wire alt. and all will work as designed
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Your current alternator is almost certainly internally regulated. 68 and earlier had external regulators.
3 wire alternators better compensate for voltage loss in the system due to long wire runs or high loads.
Your alternator "idiot light" will non longer work with a 1 wire, but the ammeter will.
If you go to a 1 wire, just be sure you run a larger wire to the horn relay. This wil minimize the effect of sensing voltage at the 1 wires alternator ouput vs the sensor wire on the 3 wire alternator.
My $0.02
Gary
3 wire alternators better compensate for voltage loss in the system due to long wire runs or high loads.
Your alternator "idiot light" will non longer work with a 1 wire, but the ammeter will.
If you go to a 1 wire, just be sure you run a larger wire to the horn relay. This wil minimize the effect of sensing voltage at the 1 wires alternator ouput vs the sensor wire on the 3 wire alternator.
My $0.02
Gary
Race Director
Joined: Sep 2001
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From: Wellington, FL
St. Jude Donor '11 thru '25
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Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
I went thru the same thing, I opted to keep the standard 3 wire setup for various reasons and purchased the chrome case/pulley etc from Summit.............took the guts out of mine and installed it in the chrome case. I also installed new brushes that you can get at Advance Auto for pennies. Works like a champ!
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
But I would say they have you talked into a 3 wire so just go that route.
