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Question regarding 1926 Model T Re: Battery Polarity Connections

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  • Question regarding 1926 Model T Re: Battery Polarity Connections

    I am new to this forum and have a question for you guys. When I built my 1926 Model T in 1962 my friend and well known Model T guru, Chris Egsgaard, instructed me to connect the positive battery pole to the frame and the negative pole to the start button. I have had it like that ever since but the car has always cranked slowly. The question is will reversing the polarity help the starter motor crank better and if I reverse the polarity do I have to be concerned with anything else except probably reversing the wires on the amp meter? Could Chris have been trying to limit fire potential which I am told can rarely happen while a Model T is at rest?
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  • #2
    Hey Hank Welcome to the VFF!!
    Nice T and the too
    3~ Tudor's & 1~ Coupe
    Henry Ford said,
    "It's all nuts and bolts"
    "Start by doing what's necessary; then do what's possible; and suddenly you are doing the impossible."

    Mitch's Auto Service ctr


    • Mitch
      Mitch commented
      Editing a comment
      Make sure all your connections are clean and tight. The frame connection should be sanded to bare metal where the cable end touches. Use the proper sized cables. Make sure it’s charging and test the battery.

  • #3
    First Hank, WELCOME to the VFF!!

    And second, to answer your question, the polarity of the battery will not change the turning rate of the starter. If you are not fully charging the battery each time you run the car, that could cause the battery to loose efficiency.

    When you drive the car does the amp meter needle come back to center, or does it always show a charge?

    If it comes back to center, then you can turn it up a wee bit, but if it's always showing a charge without any lights on, I would say the battery is weakening.
    You wana look waaay far up da road and plan yer route because the brakes are far more of a suggestion than a command!


    • #4
      Thanks for the advise. The amp needle registers a charge when the engine is running at a little above idol so I think the charging system is OK. I may need to replace the cables and clean all contact points for better cranking. I'll try that next.


      • #5
        Hank, IF you go to the local auto parts for cables, they will be too small by half because they are made for 12v. You may need to go to a vendor unless you have someone that can make up cables for you.
        You wana look waaay far up da road and plan yer route because the brakes are far more of a suggestion than a command!


        • #6

          Just ordered the cables from from Langs


          • #7
            Hank, I am new to the VFF as well. Welcome! Nice looking ’26 T!

            My ’26 roadster is negative to ground (frame) and positive to the starter switch. I believe all T’s were originally negative ground.


            • #8
              Hank welcome to the VFF you could wire your car like a modern car,i would have to check my books but i believe t's were positive ground just like ford always did. Model t's can catch fire because of the generator cut-out ask me how I know? I absolutely use a battery cut-off switch on all my cars and then no electrical fire can start. Ask away that is why we are here.


              • #9
                I agree with BNCHIEF with regards to installing a battery cut-off switch. I disconnect mine after every run. Have the type that attaches to the negative battery post.

                Here is a T wiring diagram which may be of interest or help.



                • BNCHIEF
                  BNCHIEF commented
                  Editing a comment
                  Excellent advice on your part azbob T's are more susceptible to a wiring fire than later cars. I have not looked at a T in a long time funny why ford went to positive ground after wiring the T this way.

              • #10
                Welcome to the forum Hank.
                The Model T's were neg ground, as AzBob stated. I had a Model A before I owned a T, and always thought that they were wired as yours currently is. I switched the wiring and had no problems. Good Luck. Jeff
                Twiss Collector Car Parts


                • #11
                  Bob thanks for posting the wiring diagram. I made a sticky out of it ..
                  3~ Tudor's & 1~ Coupe
                  Henry Ford said,
                  "It's all nuts and bolts"
                  "Start by doing what's necessary; then do what's possible; and suddenly you are doing the impossible."

                  Mitch's Auto Service ctr


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