12 Volt Coil Resistor Part Number (Here we go again)

If its truly a 12V Coil (3.0) ohms you need to use 2 (OEM) in "parallel" and Voltage at the Coil will be 10.V - 11.V (The resisters split the current and half the Resistance to ~ .75 Ohms "HOT".)

If its a 6V Coil then you need a RU100 (or equiv that starts at ~ 1.5 ohms) and the original Oem Ballast in "series" and the coil Voltage will be 2.4V to 3.3V

Hope this Helps,

Hope this helps. It's from www.nseries.com

If your coil is truly a 12V coil (make sure that you dont have a 6V coil) , then you don't want to be using the "voltage reducer RU-100" - you only want to be using a ceramic ballast resistor. The original dash "reducer" cuts to V too much. Check with the points opened and closed. More important than "part numbers" is the aggregate capability of the resisitor under amperage load. With proper current flow, you are looking at 10.5V-11Vs at the top of the coil. Also check and make sure that you jumper out the ignition switch which is known to cause lots of problems with time/heat related symptom problems.

Here is info on the points as I have come to understand it...

The coil fires when the points open. The reason it fires when the points open is that there is a charge in the primary windings of the coil when the points are closed and as soon as the points open the magnetic field that was present around the primary windings immediately collapses and the magnetic field energy is channeled through the secondary (high voltage windings) and the high voltage is created.The condenser is in the circuit to act as a "buffer" to prevent the charge in the primary windings from arching across the points when they open.

The high voltage that is generated in the secondary windings is discharged through the rotor to the electrode of the distributor and then through the spark plug wires to the center electrode to make the "sparkies"

Well hope that is all correct. (grin)

Regards,
Andy