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  • 55 STUDE

    1955 STUDE

  • #2
    First of all, the 6 volt starter and battery cables will work fine with 12 volts. You will need a 12 volt generator or alternator and regulator of course as well as ignition coil, 12V headlight bulbs, turn signal, back up and dome lights. A 12V system can run either positive or negative ground (don't know what you have now) but an alternator MUST be negative ground. Just remember to polarize the voltage regulator for generator systems but NEVER try to polarize the regulator for an alternator. The ammeter (if it has one)will be fine regardless of the voltage but if you reverse the ground, you'll need to reverse the terminals on the ammmeter. If it has a mechanical oil pressure guage, of course it won't make any difference to it. The existing wiring will be more than adequate to handle the 12 volts because you'll be cutting the amperage in half.

    Not for the not so easy stuff. I don't know what kind of dash light dimming mechanism you have, but I'm sure it uses a resistor of some fashion to dim the lights. With the same wattage bults, the same total amount of energy will be drawn regardless of the voltage. However, the resistance value of the resistor used to reduce the voltage for dimming will be different and you're apt to have no dimming ability at all. Without looking at a wiring diagram, I'd say you may also have to insert a resistor in the line feeding the electrically powered dash instruments. At least on many 12V systems, a resistor is already included so they can run on something like 7 volts but I'm not sure about the 6 volt system on your car. To calculate the size of the resistor needed, I'd need to know how much load there is and the existing voltage requirements.

    The radio, wiper, heater and defroster (if it has one) motor would also need to be changed to 12V or a resistor used to cut the voltage.

    Others out there that have made the conversion should be able to give you a more accurate version of what worked and didn't for them.

    I'll tell you what I have planned for my '51 when I get to working on it. I plan on using two 6V batteries and a 12 volt charging system. I'll have the starter, ignition, headlights and air conditioning motor and clutch on 12V but tap into one 6V battery to power the radio, heater, wiper motor, instruments and so on. I may have to put one battery in the trunk and run long cables to the front depending upon how much room I have left after adding the AC compressor, supercharger, power brakes etc. First I have to get the Hawk finished though.


    • #3
      John, I'd guess you're planning on isolating the 12volt items from ground to do this??? I don't think there's too many items out there set up for 12volt positive cround.[:I]

      Miscreant adrift in
      the BerStuda Triangle

      1957 Transtar 1/2ton
      1960 Larkvertible V8
      1958 Provincial wagon
      1953 Commander coupe

      No deceptive flags to prove I'm patriotic - no biblical BS to impress - just ME and Studebakers - as it should be.


      • #4
        In the 60's when I did a conversion on my '53 stude I tapped the battery (12v) and ran the gauges off 6v, and changed what was
        needed to 12v. I don't know if the new batteries can be tapped
        like that now or not. Just a thought.

        James K. Clark.
        East Tenn.
        '55 Prez 2dr Hdtp. (still 6v)
        Don't take yourself too seriously

        James K. Clark


        • #5
          I plan to use an alternator and negative ground instead of a generator. I figured I'd try to convert everything (crank and water pump drive pulley) to a multi-rib serpentine type belt since the Delco alternator, supercharger and air conditioning compressor I plan on using all use that type of pulley. I'll just reverse anything that is necessary to make things work right.

          You know James, that's a great idea you have there. I hadn't considered that since my brain was stuck in the modern type sealed battery mode, but I believe you can get reproduction batteries with the exposed connectors between cells. One of those probably wouldn't be any more expensive than two 6 volts and would save a lot of hassle. Thanks!


          • #6
            Everything is pretty easy EXCEPT the radio, if you have one. I just went through this on my '55 coupe; the PO had "converted" the car to 12V by changing all the bulbs but nothing else. You need a heater blower, defrost blower, and wiper motor from a '56 model year car and they will be a direct swap. Not sure how far forward you can go without having to make small mods but you want single wire blowers and a three wire wiper motor. You might have to change fastons to bullet connectors and/or swap harnesses between motors etc. but other than that no problems. You'll also need to reverse the wires on the ammeter and add a "Runtz" voltage dropper on the fuel gauge and another on the temp gauge. Bulb equivalents are on my web site. IF you have turn signals the front lights use a weird bulb if they still have the original sockets in them, I did find a 12V equivalent though, 1176 or 1376 will work (original 6V bulb was a 1158 - it looks like a 1154 but the pins are not indexed. I think they did it this way because they used the same sockets for cars w/o the optional directionals that used a small single filament bulb.) The rears are the standard 1034 style sockets because they always were dual filament bulbs (due to the brake lights) even without the directionals.

            You shouldn't run into issues with the wiring if the harness is in good shape because the 6V harness used heavier gauge wire than a car designed for 12V. This means that a pre-56 car converted to 12V actually has a more robust wiring harness than a later car so you can safely run halogen headlights without a relay harness (although you may wish to make one anyway.) Also the ammeter feed is 8AWG which should be OK as long as you don't run a huge alternator. I still put two 80A "Mega" fuses in my car, one at the alternator and one at the battery, to protect the harness should a dead short on one of the unfused sections occur.

            I just took the stock radio out of my car and installed a blank plate rather than fight with it. I have a "secret audio" radio which I'll probably install later on when the car is more complete and I can think about speaker locations. This may or may not be a good option for someone who wants to retain an all stock look.

            good luck


            55 Commander Starlight
            55 Commander Starlight


            • #7
              Almost forgot, the '55 battery box will not hold a common 12V battery. I did find one that would fit with a piece of wood underneath, but I forget the group number. I'll have to look next time I'm under the hood of my car. Alternately, you could try a later battery tray and see if it'll fit; I haven't tried this so I can't say that the holes are all in the same place.


              55 Commander Starlight
              55 Commander Starlight