Convert 6 volt to 12 volt

Discussion in 'Shop Talk' started by greenacresusa, Apr 12, 2006.

  1. greenacresusa

    greenacresusa Well-Known Member

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    Was thinking about converting my Ford 8-N tractor from 6 volt Postive ground to a 12 volt system. Has anybody else done this? Also any idea of how much it might run ballpark to do this? Although wouldn't think it would be too hard to do on my old Ford it's hard to tell. I don't have any lights on it yet or other accessories.

    Thanks.
     
  2. foxtrapper

    foxtrapper Well-Known Member Supporter

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    Kits run upwards of $200. If you've got an old alternator laying around, you can do it for free. Ignition coil won't like 12 volts, but it tends to take years to get around to dying. You can either use a step down resistor or a true 12 volt ignition coil.

    PS Everyone uses the GM Delco 10SI alterator. It's big and ugly and doesn't fit under the hood of an N. Using one of the japanese car alternators fits better and looks more correct. These units are much smaller and more rounded. While my current conversion has a Delco alternator, in the future I'll be using the Nipondenso units.
     

  3. John Hill

    John Hill Grand Master

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    Converting a 6V generator to 12V may only be a matter of changing the regulator. This is common practice on old motorcycles and I have done it myself.

    There are some pros and some cons. The generator will not start charging at idle so you may have to rev the engine slightly to get that charge light to go out. There is a slightly heavier load on the generator's field coil.

    But on the other hand, with twice the voltage you will need only half the amps for the same watts which makes life easier for the generator armature and brushes.

    Of course you also need to change the battery! Light globes etc. I would keep the 6volt coil and use a resistor in series with the primary but arrange it so that the resistor is bypassed during engine cranking. This is common practice on cars and gives full available battery voltage to the coil while starting. Any car ignition switch from pre-computer days should do this for you.

    But at the end of the day, an alternator is really the way to go.
     
  4. countrymech

    countrymech Well-Known Member

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    I converted my '49 front mount distributor 8N last fall. I purchased a kit through mikestractors.com, I think it was 154.99 with free shipping. You can do it yourself by buying individual parts if you already have an old AC Delco alternator but chances are good that unless you have a machine shop or a welder you'll have to buy the brackets. I opted to just buy the kit and be done with it, the only thing that wasn't included was the new battery. It came with a new coil, alternator, brackets, belt, wiring harness, etc as well as instructions. The best thing I ever did for that old tractor. I was starting it up all winter even on the coldest of days and had plenty of power to spare. Here is a link to a similar conversion http://home.earthlink.net/~8ntractor/id4.html
    Good luck and if you have anymore questions please keep us posted. Paul
     
  5. greenacresusa

    greenacresusa Well-Known Member

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    Thanks for all the great information!! I'm going to see about doing this with a friend that's really good at working on tractors. I'll print out this information and have him go over it. And the link to http://home.earthlink.net/~8ntractor/id4.html
    is great!!!!

    Thanks again!!
     
  6. Wildtim

    Wildtim Well-Known Member

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    heres a link to a discussion board on 8-n's, their a bunch of really knowlegable guys who can help you out: http://www.ntractorclub.com/forums/nboard/nboard.htm

    Also a real good place to do business with who will actually expain the process over the phone with you and give to great customer service:
    http://www.just8ns.com/

    From what I hear though If your six volt system is in good shape changing over to 12 doesn't make much difference, unless you want to run electric accessories. But if your system is running down or broken it mmight actually be cheaper to switch than to try and find the old six v parts. My old N already had 12 installed when I got it and it does take away from the look of the tractor but my old thing has been rebuilt/painted so many times that that is just the start of ugly. :nana:
     
  7. Beeman

    Beeman Well-Known Member

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    It's worked for over 50 years already, what's the reason for changing? When converted they have a tendancy to burn points if everything isn't perfect which would then be fixed by electronic ignition.
     
  8. mink

    mink Well-Known Member

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    i had an old farmall m that i put a 12 volt battery in. i just pit a 6 volt resistor in the line going to the coil. the generator always kept the battery up.....mink
     
  9. fixer1958

    fixer1958 None of the Above

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    I've converted 2 AC WD45's and a JD 60 to an alternator 12V neg ground. The JD was already 12V. It's easier for me because of trying to find 6V bulbs etc. The biggest advantage is the 6V starter cranks alot faster on 12V (starts faster in really cold weather). You just have to make sure your cranking times are shorter because it will get hot alot quicker but no real ill effects from it. The starter doesn't care if it's pos. or neg. ground. You could always get it rewound for 12V for about $150. I just got a AC Delco 35 amp alt and put a self exciting regulator in it. The only wire to the alt is batt. pos. Used the pulley off the old gen. because of belt width. Run up the rpm's for a second and it kicks the alt in and your good to go. Also, be sure to put the resistor in the dist. pos. side or you will be burning points up every other day.
    You can tell if it works or not by pulling of a batt. term and if it dies it's not working. The ignition won't work on positive thoughts alone.
    Works for me.
     
  10. HermitJohn

    HermitJohn Well-Known Member

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    Yes the little alternators are nice for conversions where the Delco is just too big. Try one off a Festiva or a Metro. Unfortunately they are pricey as all get out. Around $100+ rebuilt. I had great tiny alternator on my old '72 Courier, tiny yet lasted forever. External regulator which I eventually replaced with 60's era GM regulator, but alternator itself was same one that came with Courier when I bought it. Alas when I priced one at parts store to use on something else, it was cheap enough, but when they brought it out, it wasnt same, was larger. Apparently enough space on Courier engine that bigger one would fit and parts people just made one later alternator fit some previous applications so one less part to carry.

    By way I am going to eventually run into this on my '62 MF65. It has 12v generator and they have low output and are unnecessarily expensive to rebuild anymore compared to just buying a rebuilt alternator. No space for a GM alternator without it sticking way off side of engine, so planning on just using tiny one off my Festiva when it goes and putting a rebuilt GM on the Festiva. The Festiva does have room for the GM, just have to make bracket. That also means its no biggie to replace if I am away from home and GM alternator goes. Every auto parts store in USA would have GM alternator in stock and for cheap.