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ignition coil wire

B

bodyman1

New User
Hi guys, On a Farmall 140 the wire from the distributor does it go to the positive or negative post on the coil ?
I check my other tractors A , C , 140 , 240, 340 they are not all wired the same. Does it matter ? Does 12 volt or a 6 volt positive ground make a difference ? Thanks for any INFO
 
(quoted from post at 09:26:43 01/17/18) it will work either way but the wire is supposed to go to the negative side of the coil
Click to expand...
I wish they would restore the edit button sorry but I was thinking about a 12volt system not sure about the 6 voltsystem
 
I was always told the if the tractor is neg ground, the wire to the coil went on the positive side of
the coil. If it is pos ground, the wire going to the coil went to the neg side.
 

The wire from the coil to the distributer is basically a ground wire. In other words, when the points close, the electricity is directed to ground. So, if your tractor is a positive ground system, then the positive + side of the coil should go to the distributer. If your tractor is a negative - ground system, then the negative side of the coil should go to the distributer.
 
While a coil will still produce a spark if wired at the incorrect polarity, I advise it be connected to match the tractors polarity. + to distributor if POS ground - to distributor if NEG ground.

John T
 
The polarity at the coil primary needs to be correct so that the polarity at the spark plugs is NEGATIVE. This ensures that the smallest voltage is necessary to fire the plugs, as it requires less potential for the spark to originate at the smaller electrode (the center) instead of the outer electrode.
 
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