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  1. #1
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    Default Switch Ford 640 to 12 volt? (6 volt now)

    What's involved and what's the approximate cost to switch a 1956 Ford 640 to 12 volts???

  2. #2
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    Hmmm....I found a 12 volt conversion kit here: http://www.ytmag.com/cgi-bin/store/s...;r=nseries.htm

    Is that all I'd need???

    Oh and what about the starter? Still work after the 12 volt conversion?...any other issues?

  3. #3
    Epic Contributor jinman's Avatar
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    </font><font color="blue" class="small">( Oh and what about the starter? Still work after the 12 volt conversion?...any other issues? )</font>

    The kit you saw at ytmag will probably work if it's the one for the late model 8N that does not include a coil. The biggest problem you will have is getting your alternator pulley and tension adjuster arm modified for the alternator. I took the pulley off my generator and mounted it on the alternator (if I remember correctly). Of course your voltage regulator comes out or you can just disconnect it and leave it in place.

    The kit I saw at ytmag comes with a ballast resistor. This kit expects you to keep the 6V coil and for that you will need the ballast resistor or you will burn up the coil and points. If you get a regular 12V coil, you will not need the ballast resistor.

    When you put the new battery in, it will most likely be 12V negative ground. Even though this is opposite to the 6V battery, your starter doesn't care. It will still turn the correct direction. The easiest way to explain it is to just tell you it's "magic." [img]/forums/images/graemlins/wink.gif[/img]

    One thing you may need after awhile is a new starter solenoid. My old 6V one fried after a couple of years. As a matter of fact, the engine started and the starter kept going after I released the starter button. I had to disconnect the starter in a hurry to get it to stop turning because the solenoid welded together. Some will say that with 12 volts, you don't pull as much current as with 6V, but the starter turns over faster and the power dissipated (volts x current) is higher for the 12 volt system.

    If you can find a kit for the NAA or later tractors, you will be a lot better off than buying one for an 8N and modifying it. I just bought all the parts and put mine together. If you have a local starter-generator shop, they might offer you lots of help. My local guy had done lots of 12V conversions and had almost all the parts needed in stock. Many New Holland dealers also have a 1-wire alternator conversion kit they sell. There's no need to experiment if you will spend a little time and check around. [img]/forums/images/graemlins/cool.gif[/img]

  4. #4
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    Thanks for the tips. We have a New Holland dealer close by. I might check with them. This is for my wife's grandpa's tractor who lives next door. His battery keeps going dead and we're not sure what the cause is...so he's always rolling it down the driveway and popping the clutch to get it started...LOL He claims he took the battery somewhere and they said it was fine after testing it. So maybe the voltage regulator?...or maybe the generator going bad? I'd just assume fix it if it's much easier than converting to 12V.

  5. #5
    Epic Contributor Soundguy's Avatar
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    I definately recomend getting the NAA and up kit. The kit comes with brackets to fit a delco 10-si alternator correctly. My NAA has this bracket kit. No muss no fuss.

    Do yourself a favor and get a napa IC14SB ignition coil. it's about 15$ and will give you more KV than your oem 6v coil and a (wastefull) dropping resistor.

    Your starter and ignition switch and amp meter won't care.. and your solenoid shouldn't. My NAA is still on its oem solenoid.. though i finally had the starter rebuilt last year finally.

    Another option is to simply have the genny rebuilt as 12v... shops do it all the time.

    Also remember to hook up your ignition coil correctly in relatio to your new battery polarity. Consider your points as ground.. so if you are neg grnd.. put the coils - terminal to the points.. etc. Your oem col may have said batt/distrib and that would have been for pos grnd... neg was bat, and positive was distrib.. etc.

    Soundguy

  6. #6
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    Well I went ahead and switched it over for him today. He called the New Holland dealer and they had the conversion kit in stock. I'm sure it's the same thing they sell on the internet because it looked just like the kit in the link I sent. Had the Delco altenator, resistor for the 6 volt coil and a wireing harness. I ended up not using 2 of the wires in the wire harness. I re-used the starter switch wire for one thing. We didn't bother switching out the coil for now. Anyway after I got it all installed (took maybe 45 minutes?) I crossed my fingers, turned on the ignition switch and hit the start button. Vrrroooooom! [img]/forums/images/graemlins/smile.gif[/img] Works great.

    The only thing I wonder about right now is the amp gauge has stayed around +10 for the few minutes we've had it running. Haven't had it running for more than 10 minutes total maybe...so maybe it just needs to charge the battery before it'll go down? The battery is new but looks like it had been sitting for awhile.

    Hope it stays running well from now on [img]/forums/images/graemlins/smile.gif[/img] I'm sure he was getting tired of roll starting it (popping the clutch to get it going). He's 75 now and needs help to get it going...but now he can jump on and crank 'er up by himself.

  7. #7
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    And just to make sure I didn't do anything boneheaded...here's what I hooked up (let me know if something is wrong). The old wiring harness had been modified and the directions for installing the conversion kit was a little lacking. So basically I had to use my knowledge of auto mechnics to improvise just a tad.

    Here's what's connected:
    New altenator - red wire from terminal to amp gauge.
    Other side of amp gauge to starter solenoid.
    Jumper from amp gauge to ignition switch.
    Other side of ignition switch to resistor - other side of resistor to 6V colt.
    Starter switch to terminal on soleniod (this didn't change - used existing starter switch wire).

    Nothing else changed.

    Basically it looks like all I had to do was feed power through the amp gauge and to the battery - from the altenator. Then feed power from the battery (via the amp gauge, via the starter soleniod terminal) to the ignition switch. Connect other side of ignition switch to the coil (via the resistor) - ignition switch simply cuts power to the coil.

    That sound right?

  8. #8
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    Here's a crude drawing that shows what I have...
    Attached Images Attached Images

  9. #9
    Epic Contributor Soundguy's Avatar
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    Make sure the ignition switch is hooked up on the 'incoming' side of the ammeter.. that way when the ignition switch is on ( and points closed) that the meter shows a 1-4 amp discharge.

    Also.. check on your ignition coil. Since you are neg grnd now.. make sure the correct side of the coil goes to the distribuitor.

    OEM coils might say ( batt and distribuitor ) in that case.. the distrib is pos and batt is neg. If it has +/- simply hook up like polarities.. etc.

    Charge should taper off after a few minutes depending on battery state.

    I'm guessing this is a 1 wire job. They are not as desireable as the 3 wire jobs.. but they make do.

    Soundguy

  10. #10
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    Default Re: Switch Ford 640 to 12 volt? (6 volt now)

    I'll check it out first chance I get...

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