12 volt coil compatibility

point3dave · Jan 4, 2009

Hi I can get a 12 volt coil for a 194? s M for $25 in local parts store. Will a new one for 1960 chevy work? I have one of these on hand. Thanks Dave K

Mike Groom · Jan 4, 2009

It should work O.K.,my only concern would be if you have an external resistor or not some of these coils had an internal one that dropped the voltage to the points,you could check that with a meter and verify the output voltage to know if you need a resistor or not.

glennster · Jan 4, 2009

if it is a 12v coil, you can still use it on your m, even if the tractor is 6v. zip on over to your local napa, pick up an ignition ballast resistor for an early 1970's b body chrysler . they are about 4 dollars, its a ceramic looking doo- dad with 2 terminals on it. hook your battery power to one side, the other termainal goes to the coil .

old · Jan 4, 2009

My Ford 841 has had a coil off a 1969 Chev pick up on it for over a decade now and has worked just fine that way. So simple answer is YES
Hobby farm

Bob · Jan 4, 2009

Use a NAPA IC14SB or equivalent.

It is a TRUE 12-Volt coil, so you WILL NOT need to use a resistor with it, and the price SHOULD be less than the $25.00 you were quoted.

Janicholson · Jan 5, 2009

I think his tractor is converted to 12V from 6. With respect, (I know you know this) the use of a 12v coil on 6v system with a resistor won't work. JimN

mkirsch · Jan 5, 2009

(quoted from post at 09:24:36 01/04/09) if it is a 12v coil, you can still use it on your m, even if the tractor is 6v. zip on over to your local napa, pick up an ignition ballast resistor for an early 1970's b body chrysler . they are about 4 dollars, its a ceramic looking doo- dad with 2 terminals on it. hook your battery power to one side, the other termainal goes to the coil .

If you use a true 12V coil AND a resistor on a 6V system, the spark will be extremely weak, if it sparks at all.

The 12V coil already has one resistor in it that cuts the voltage roughly in half. If you put 6V to the coil, it'll see 3V through the resistor.

Adding an external resistor will cut the voltage by half again. Now instead of 3V, the coil will only see 1.5V, about as much as a flashlight battery.

Owen Aaland · Jan 5, 2009

(quoted from post at 08:39:30 01/05/09)

....... The 12V coil already has one resistor in it that cuts the voltage roughly in half. If you put 6V to the coil, it'll see 3V through the resistor.

Adding an external resistor will cut the voltage by half again. Now instead of 3V, the coil will only see 1.5V, about as much as a flashlight battery.

A 6 volt system should not have any resistor in the circuit.

Other than that you have the right idea but the math will be a bit off. Adding the resistor to a 12 volt coil that has an internal resistor will only add about 50% more resistance rather than 100%. Assuming that the resistance of the external resistor, the internal resistor, and the coil windings are all equal, the voltage after the internal resistor will be four volts rather than three.

It really doesn't make much difference because either way the voltage will be too low.

12 volt coil compatibility

point3dave

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Mike Groom

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glennster

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old

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Bob

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Janicholson

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mkirsch

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Owen Aaland

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