2n ford

changed the 2n to 12 volt today --used the kit from this sight - went fairly well -- it comes with a 12 volt coil and a voltage reducer -- put in the new coil and the reducer -- runs like crap with reducer --and good without -- why do they send a reducer if ya dont need one?why woudnt the old 6-volt coil work by just adding the reducer -- I am confused a bit -- Roy

Your 2N had a wire wound ballast resistor on the back of the dash.
You need that regardless of 6V/12V, so make sure it is there and wired
in correctly. After that, if you have a 12V coil you should be good.

If you have 6V coil on a 12V conversion, you may need an additional
dropping resistor. The value of that resistor would be determined by
current flow. What comes in any kit, from any source, is likely wrong.

I can't tell you why they include it with a kit that comes with a 12V
coil unless they don't quite understand the original ballast resistor.

The reason for the resistors ahead of the coil is to get the amp draw on the points in the correct range to give points long life and get sufficient spark to the plugs.

The goal for a 12v system is to get about 3 ohms resistance across the coil and all resistors.

To check the resistance, you'll need to remove the cap, connect one lead of the meter to the non grounded side of the points (be sure points are open), the other lead to the ignition side of the ignition switch (switch off). What you will be reading is the resistance through the primary side of the coil and all resistors.

If the reading is low, 2.5 ohms or lower, the load on the points will be too great. The coil will over heat, the points will be short lived. But it will have a powerful spark, while it lasts.

If the reading is too high, 3.5 ohms or higher, the spark will be too weak.

A simpler test is to check the voltage at the coil primary terminal. With the points closed, ignition on, with the 12v coil in place should get around 9 volts. The same results will apply, high voltage will give hot spark, but overload the points. Low voltage will give insufficient spark.

My concern is possibly the coil and resistor included in the kit are correct, and there is another problem with spark delivery, like bad wires, rotor, cap, or plugs. By removing the resistor, you upped the spark, but will be overloading the points.

"The goal for a 12v system is to get about 3 ohms resistance across the coil and all resistors."

If you can measure primary circuit Amps accurately, and the draw is 3 Amps or a bit more, all is well.

But that's too simple/too little drama for most posters here, IMHO.

(quoted from post at 23:19:07 06/16/18) "The goal for a 12v system is to get about 3 ohms resistance across the coil and all resistors."

If you can measure primary circuit Amps accurately, and the draw is 3 Amps or a bit more, all is well.

[b:18886988d3]But that's too simple/too little drama for most posters here[/b:18886988d3], IMHO.

Click to expand...

For sure.

I know nothing about the 12 volt conversions. I have a 2N Ford since May of 1944 when it came to us new when I was just a few months old. That resistor on the dash should never have been put in at factory. You will find it is the cause of most starting and running problems. Get rid of it and they will start and run just fine on the 6 volt. The reason 8 volt batteries were put in was to get the voltage up high enough to start the tractor because that 4.6 volts comming out of that resistor just is not enough to do it. It will not make the points to burn if you get rid of it. It will let the points have the same power to them as JD, IHC and Chevy ran on all the time. It will also make the tractor stop after running for a while and perhaps be able to get it started again after an hour. I was having that running trouble and after replacing several switches and other parts I took a wire and bypassed the resistor with its own switch. With the factory switch it would not run good or shut off. With that extra switch when it srarted to run bad and die just turn that extra switch on and run perfect and shut offfactory switch and still ran perfectly. Turn factory switch back on and shut off the extra switch and it would start to die, turn the extra switch back on and it would come to life again. Rite now tractor is down for head gasket replacement that was put in back in either 70's or early 80's.