Question about 12 volt conversion on a M

Anonymous-0 · Aug 19, 2008

I am trying to convert my M to 12 volts. The 12 to 6 volt reducer I bought for the coil wire didn"t reduce the voltage at all and ruined the coil. Can I just remove the reducer and use a 12 volt coil instead? If I do will I need to modify any part of the electriacl system? Thanks

JOSSETTE · Aug 19, 2008

did you switch the wires at the ammeter?

Allan in NE · Aug 19, 2008

My M is running on a full 12 volts. Runs just fine.

Will probably need points in another 6 or 7 years.

Allan

John T · Aug 19, 2008

On a 12 volt tractor YES you can EITHER use a full true 12 volt coil (NO Ballast required) or else a 6 volt coil with a voltage reducing (12 to 6) external series Ballast Resistor. A full true 12 volt coil dont require any ballast on a 12 volt system and has a priamry resistance in the neighborhood of 2.5 to 3.5 or so ohms. Theres nothing else required in the ignition priamry system wiring if its a 12 volt coil on a 12 volt system.

Yous sure the voltage reducing ballast resistor was wired correct in series with the coil after the switch and ahead of the coil??? If it were a good ballast (ohms around 1.5 to 2) and was wired correct it should have reduced the current and voltage on a 6 volt coil so it will work and not burn up???

John T

GA Dave · Aug 19, 2008

Click this link. It'll walk you through the conversion. David............http://www.ytmag.com/articles/artint131.htm

Janicholson · Aug 20, 2008

My only thought is that You might have purchased an elecrtonic device to use 6volt accessories on a 12v system. It would be a box like thing with several wires. If so it will not power a coil. There is drastic electrical "noise" in that application that will toast the electronics in the device. Ignore the above if it was a ballast resistor as indicated below.
The use of a sensitive meter on a ballast resistor under no load can also show full system volts (12) when in fact it will drop the volts once it is placed in the circuit. JimN

JMOR · Aug 21, 2008

(quoted from post at 19:51:26 08/19/08) I am trying to convert my M to 12 volts. The 12 to 6 volt reducer I bought for the coil wire didn"t reduce the voltage at all and ruined the coil. Can I just remove the reducer and use a 12 volt coil instead? If I do will I need to modify any part of the electriacl system? Thanks

If you just go to auto store and ask for a "ballast resistor", you can and will get anything from about 0.3 ohms up to about 2 ohms. Almost a 7 to one ratio. The 0.3 will not do much voltage reduction at typical 3 amp coil current. 0.3 ohm X 3A=0.9 volts. Far from a 6v reduction!
2 ohms X 3amps=6volts
You just never know what the parts guy will hand you.

Question about 12 volt conversion on a M

Anonymous-0

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JOSSETTE

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Allan in NE

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John T

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GA Dave

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Janicholson

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JMOR

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