Help with Alternator Install

Electrical and Ignition

  1. VanceC

    VanceC Well-Known Member

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    I drove my 65 Dart home from the shop that installed a new 318. It ran fine but when I parked it wouldn't start. The green wire for the alternator was disconnected. I had the battery and alternator tested and the alternator failed. I now have a new alternator but I don't know which of the two terminals (A and B in my photo) the green wire goes on.

    Alternator Contacts.jpg

    Alternator.jpg
     
  2. cudascott

    cudascott It’s a sickness!

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    FC6C2177-1ADC-4632-8946-6060C1F381F0.jpeg CB65B92D-D587-4D63-A696-4355EAE74E55.jpeg first off here has your car been upgraded
    to the solid state voltage regulator? the square back alternator in your pic is a late model unit. The round back alternator is what came originally on your car.
    the first pic is the early regulator and second is the later one.
     
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    • Kendog 170

      Kendog 170 Let the boy go !

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    • Early a body

      Early a body Well-Known Member

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      green wire went to original single field alternator, the other wire went to something else but not the alternator. - maybe a temperature gauge sending unit- or something attached to the coil.

      You are showing us a square back alternator that would require 2 field wires. You would have to add a field wire in to have the alternator wire charge and the above pictured electronic voltage regulator. Google Mopar charging system upgrade. its an easy job to wire in.
       
    • SIX225

      SIX225 Well-Known Member

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      You should be able to use the two terminal alternator with your current wiring if you ground one of the 1/4" field terminals (doesn't matter which one). I made a small jumper and grounded mine to the case.
       
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      • VanceC

        VanceC Well-Known Member

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        Do I still need to replace my voltage regulator with a later solid state one? Also, I don't know anything about electrical; where is the voltage regulator? Thanks
         
      • Early a body

        Early a body Well-Known Member

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        not sure about the voltage regulator as i upgrade all my cars to the 2 field set up. The voltage regulator is located on the firewall to the left of the master cylinder square black box , if its the original one end should say field
         
      • Dana67Dart

        Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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        Hey Vance.

        Short answer is connect green wire to "A"

        The "B" terminal has been cut off by the rebuilder indicating that it is internally shorted to ground. You can check with a multimeter.

        Long answer...

        If you have a stock charging system in your 65 than you have a single field wire voltage regulator (top photo in post #2)

        It has one wire going into it from an ignition key source, and one wire going to the field of the alternator,

        Back in the day you had a "round back" alternator that had only one field terminal. Those alternator cores are few and far between so rebuilders now use the 2 field wire ( isolated field for some of our members) cores and short one of the feild terminals internally. That leaves only one field terminal. This makes it functionally equivalent to the round back with 1 field terminal.


        You do not need to modify anything on your car to run the alternator you show in your photos. (ASSUMING YOU HAVE THE STOCK CHARGING SYSTEM)
         
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        • Mattax

          Mattax Just the facts, ma'am FABO Gold Member

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          No.
          Just ground one of the field terminals as shown here: Identifying Chrysler Alternators (1960-1976)

          While ther eyou can read about how the alternator works.

          And I hope you still have the original alternator.
          In some cases its worth fixing.

          Before starting the engine, charge the battery with a battery charger.
          explanation here:Charging Battery with Alternator - Warning
           
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          • Dana67Dart

            Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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            "B" is already grounded as indicated by the terminal being cut off.

            Or at least sell it to someone here as a round back core. Might even be able to make money on the deal!

            Lastly measure the diameter of the pulley if it measures 2.75ish vs 2.5ish you will see a fluctuating ammeter but it will still work ok.
             
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            • Mattax

              Mattax Just the facts, ma'am FABO Gold Member

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              Good observation! bowdown-gif.gif
              Bet you are right.
              And you are also right that it is best to check with a multimeter just to be sure.
              thumbs_up-gif.gif
               
            • Dana67Dart

              Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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              I only know cause I just went throught this exercise a few months ago. Tried to get a round back alt and nothing doing.

              Bit the bullet on a square back ( now my emergency spare)
              And it looks identical to the one in the photos. Even the poorly cut off terminal looks the same.

              My bet is if you remove the screw holding terminal B on you will find there is no insulator. Between the screw and the terminal, install the proper insulator and it becomes an isolated field ( 2 wire to us rednecks) alternator
               
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              • VanceC

                VanceC Well-Known Member

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                So... how about I connect the green wire to A and also make a jumper to ground B to the alternator body just to be safe? And does any of that depend on which voltage regulator I have?
                 
              • Dana67Dart

                Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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                Not needed. You are overthinking things.

                Use a multimeter and measure resistance from B to the case of the alternator. Should read 0 ohms or real close to that.

                If you have an electronic regulator like photo 2 in post 2 then you have the wrong alternator.

                Post photo of your regulator
                 
              • VanceC

                VanceC Well-Known Member

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                This is my regulator.

                IMG_1206.jpg
                 
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                • 1969383S

                  1969383S FABO Gold Member FABO Gold Member

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                  That’s why after trying to purchase a rebuilt round back, I got frustrated and just rebuilt my own! Either I got a square back single pulley which would work fine, or a dual pulley square back.

                  Glad I rebuilt my own! Was not that difficult and the parts were available!
                   
                • 67Dart273

                  67Dart273 FABO Gold Member FABO Gold Member

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                  THIS HERE with your regulator

                  In 69/ earlier, alternators normally have one field/ brush connection, the other is grounded
                  In 70/ later BOTH field/ brush terminals are supposed to be insulated from ground

                  So check the one you bought, and you can usually tell visually by the insulation washers or lack of them.

                  The 69/ earlier has one field connection

                  the 70 and later (to convert) needs two field connections both insulated from ground and add one more wire (if converting a 69 to a 70) and buy the new VR
                   
                • cudamark

                  cudamark FABO Gold Member FABO Gold Member

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                  Since you have a rebuilt alternator now, I'd install a new regulator too. I'd get the newer version of the '69 and older style that is all solid state, not points type.
                   
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                  • RustyRatRod

                    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                    No need to replace the regulator with a later unit. Just confirm B is grounded with a meter and hook the green wire to A as others have said. I have a square back alternator on mine just like that still running the older style regulator and it works just fine. I just made sure one field terminal was grounded and hooked up the green wire to the other. Works fine.
                     
                    Last edited: Jun 4, 2021
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                    • VanceC

                      VanceC Well-Known Member

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                      I was stumped when I tried to install the new alternator; it didn't fit. Took it to my local auto shop and turns out the alternator they gave me is the wrong one. He put in the right one but had to replace the voltage regulator to get everything working. Both are right for my early a. Thanks
                       
                    • cudascott

                      cudascott It’s a sickness!

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                      Glad you got the correct alternator and it’s all sorted out:thumbsup:

                      Rebuilding an alternator although easy enough with the right tools just isn’t for everyone. CFB3E9A4-70C3-4506-A698-16F567775930.jpeg 9E6B48C8-57C9-4C03-B283-0B4D47CCB76A.jpeg 98646E35-0DB5-4877-8902-B831BED9EDE6.jpeg D07433CE-7234-4A9A-829C-276DD5B594C6.jpeg FB4F5BA1-3CAC-48FC-9B36-77E594709C76.jpeg 34585CC8-4605-4526-92BF-4FFAE407DCAC.jpeg 31EB5092-762C-44EE-9515-BCFC0E89E080.jpeg
                       
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