Ignition resistors
 

Heres a question for some of you gurus to ponder: all of the 6v fords, from abou 32 and up use an ignition resistor in the primary side of the ignition so the points won't burn. Why doesn't Model A and most other 6v cars of that era use one?

Re: Ignition resistors
 

They have an internal resistor - inside the coil?....

Re: Ignition resistors
 

The resistors on the 6v ignitions is a ballast resistor, which means it changes resistance as it heats up. It is more a factor of how the system is designed, you can use a "can" coil with a 6v and it does not require a ballast resistor. Ford designed to coil to work at a lower voltage combined with a ballast resistor. This has the advantage of increased voltage at start-up (cold ballast resistor) and then reduced current to the point after warmed up (hot ballast resistor). It is just the design Ford went with.

Note: Because of the meds I am currently on, my responses may or may not be totally coherent!! :)