In Reply to: 2n runs fine posted by John S on January 24, 2019 at 07:04:01:
“I had checked my battery voltage and it was at 11 volts.” That would cause hard to no start
“What I was trying to find but couldn't in any Ford books was a good explanation of how the electrical system works and what the purpose and value of each component is supposed to be.” Do an internet search for “Kettering Ignition”, “breaker points”, “ignition coil”, “ignition condenser”, “resistor” and other related terms. Also do a search for “Ohm’s Law” as this will help explain the purpose for added resistance.
The basic theory of operation is the same for all distributor ignition systems. The Ford front mount distributor is unique in it’s design, construction, and mounting of the components.
Others have explained the front mount ballast resistor. You do not use additional resistor with 6 volts, but would add a resistor if using 6 volt coil in 12 volt conversion.
“I had read that the front coil has a primary and a secondary winding in it, but could not find what the voltage values are supposed to be or how I can check those.” Can type coils also have a primary and secondary winding in them. Coils are transformers with one side of primary and one side of secondary tied together.
You can “check” a coil with an ohm meter. Primary on 6 volt coil should be approximately 1 1/2 ohms and direct 12 volt about 3 ohms. Secondary approximately 6500 to 10000 ohms. It is difficult to impossible detect a shorted coil with an ohm meter, but significantly higher resistance readings indicate a defective coil that needs to be replaced. To “test” a coil would require equipment found in a specialized shop. In short, don’t worry about it...if coil works use it, if not replace it.
The difference between a 6 volt or 12 volt “external resistor required” coils and a direct 12 volt “no external resistor required” coil is in the internal winding. The difference is in the wire used to wind the primary side. There is no added resistor inside the can connected in series with the coil primary.
“for the side mount tractors and there is no resistor so how come?” Because of the way the coil is designed and constructed.