1940 Ford 9N no spark.

Spfeffer

New User
I recently inherited a 1940 Ford 9N. There has been some mods done to the tractor. It is still 6v but seems to be negative ground. My father-in-law last had it running a few years back. it cranks over but there's no spark. I replaced the points, condenser and rotor cap. Bench checked the conductivity of the distributor. I don't know what to check or how to check the rest of the system.
 
Run a simple hot wire to the coil from the ignition side of the battery. If you then have spark or it fires up the problem is from the coil back to the battery
 
When system polarity changes coil polarity also changes . Ensure it is neg ground , then make sure coil is wired for neg ground. You don't just change polarity without rewiring coil. So if someone did that without wiring coil polarity it could cause that.
 
Just for your info. On the 9N 2N and early 8N one can not change the coil from + ground since it only has 1 wire on it. Those are the front mount distributor where they used the square coils that had only the ignition wire hook up on the coil and the ground is internal to the distributor
 
(quoted from post at 08:49:44 07/21/16) When system polarity changes coil polarity also changes . Ensure it is neg ground , then make sure coil is wired for neg ground. You don't just change polarity without rewiring coil. So if someone did that without wiring coil polarity it could cause that.

The negative side of the battery is grounded to the frame and the wire from the generator to the battery shows positive volts when I put the positive lead on it and negative lead on the frame. Can the coil be rewired or to I have to buy a new one?
 
Coil cannot be rewired and a new coil will still be made for + ground. That said there are thousands of the old front mount distributor tractor being used all day long with - ground and 6 volts and lots with - ground and 12 volts.
Not having spark can be a number of things and that is why I said to try a hot wire that way you know which way to find out why you have no spark. But do not leave it hot wired a long time since that takes out a ballast resister in the system so you can burn out a coil if left that way for a long time
 

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