I need some info from you sparkmasters....

Animal · Dec 26, 2012

This is on a farmall M that I am redoing. It is converted to 12 volt negative ground. I got a repro stock coil from Steiners for this thing and it was recomended to me from their service techs to have a balast resistor in the line going to it. I am running about four feet of 10 gauge wire from the resistor to the coil and it sure has a weak spark from the coil to the plugs. I ran a jumper from the starter to the plus side of the coil along with the low voltage wire and it will fire real good as long as the starter is engauged, when I let up on the starter the motor will not hit. I am thinking that I have to long of a run on small wire going to the coil. What do you fellas that really know your electricity think. I value your knowledge alot on this board. Thanks in advance, Animal..

Animal · Dec 26, 2012

Something else that I forgot to mention, when you put a test light on the plus side of the coil it will blink when you turn it over kind of like the negative side of the coil except it goes from dim when the points are closed to real bright when they are open. I do not recall seeing this on the old cars that had points and condensors. Is this normal? It also has new points and condensor.

JMOR · Dec 26, 2012

(quoted from post at 20:24:02 12/26/12) This is on a farmall M that I am redoing. It is converted to 12 volt negative ground. I got a repro stock coil from Steiners for this thing and it was recomended to me from their service techs to have a balast resistor in the line going to it. I am running about four feet of 10 gauge wire from the resistor to the coil and it sure has a weak spark from the coil to the plugs. I ran a jumper from the starter to the plus side of the coil along with the low voltage wire and it will fire real good as long as the starter is engauged, when I let up on the starter the motor will not hit. I am thinking that I have to long of a run on small wire going to the coil. What do you fellas that really know your electricity think. I value your knowledge alot on this board. Thanks in advance, Animal..

feet of 10GA wire is definitely not your problem! I first suspect that your resistor has too great of a resistance. Do you know what value it is? Do you have an amp meter capable of measuring about 4 amperes?
Yes, the light dims because the resistor is doing what resistors do when current flows through them, that is, they drop voltage.

Animal · Dec 26, 2012

No sir I sure do not know what its value is.

old · Dec 26, 2012

Last time I did a 12 volt conversion on a Farmall and used the factory 6 volt coil I used an O'Reilly's VR-1 ballast resister. Cost around $5 and it works very well on any tractor I have done and I have done a good many. Plus it can be mounted so as to be hidden if you have a hole some place to mount it at

old · Dec 26, 2012

If your spinning the engine over as the points open and close yes a test light can in fact sort of blink

BillM (OH) · Dec 26, 2012

I would get a 12V coil from Napa that needs NO resistance and ditch the existing ballast resistor. 10 gage wire is way more than you need. I would also make sure you have copper core wires for the plugs and the coil output.

Animal · Dec 27, 2012

I want to thank you all for your help. After spending a couple of hours messing around with no luck, I put a regular coil off another tractor on it and it fired right off. I went to town and got a new internal resistance coil and ran my 12 volts to it and now its purring like a kitten. I learned a valuble lesson on this tractor. Take all those foreign reproduction parts that don't fit or don't work and stuff them!!! So much for factory original reproduction parts, I am done with them unless they are made in the U.S.A.

souNdguy · Dec 27, 2012

if you think 4' of 10g wire is killing the spark.. time to sell the M

larger wire is great for conductance.

better check that switch or the resistor..

something other than 4' of AWESOME copper conductor is killing the spark.

me? I'd loose the blasted 6v coil and resistor and get a real 12v coil like a napa ic14sb.. 16$ etc..

I need some info from you sparkmasters....

Animal

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Animal

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JMOR

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Animal

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old

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old

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BillM (OH)

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Animal

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souNdguy

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