The Stovebolt Site Forums The Shop Area The Electrical Bay Clarification Balast resistor = ignition resistor?

Good morning! As I read through various discussions I see the mention of "balast resistor", "igintion resistor" and "voltage reducer".
I'm converting to a 12volt with the original 1949 foot start 216 ci engine. I have purchased a 12V coil with "no external resistor rewuired 1005" written on it. It is a BWD select E502.

SO the question is; if I have an internal resistor (in coil and I assume it is a balast resistor) do I need an ignition resistor? Plus I assume there is no need for a side terminal on the starter switch and a wire to the start (key) switch, etc.

THX for your help,

ia49,

You have it figured out...the coil with the internal resistor takes care of all your concerns, no other goodies required.

Stuart

Balast resister & ign. resister are the same thing. Voltage reducer is used to cut the voltage down for 6 volt acess. You must use one for your gas gauge or you won,t get a 2nd chance.
It,s correct the no resister required coil doesn't need a resister or bypass, but personaly I wouldn't use one. They are designed for tractors & low RPM engines. Maybe a 216 might be considerred a low rpm engine but the manufactors never used them on highway vehicles.

Internal resistor 12 volt coils were standard on a 1950 John Deere A which was around 320 cu in engine with 2 cylinders which ran around 900 rpm if that tells you anything.

Ford ran millions of internal resistor coils for at least 30 years, on street machines! The only disadvantage with them is a slightly lower spark voltage during starting because it's impossible to bypass the resistor while the starter is running. If battery voltage drops to 10 volts during cranking, for instance, the internal resistor reduces this voltage even more, resulting in a weak spark when you need a hot one most. GM systems used the "S" terminal on the starter solenoid, or the "S2" terminal on the ignition switch to bypass the resistor and put straight battery voltage to the coil primary. When the starter disengaged, the resistor kicked in and dropped the voltage back to approximately 9.5 volts to the coil primary terminal during normal running. This saved the points from premature failure with the low-resistance coil primary winding.
Jerry

Ford went to 12 volt system in 1956. All the ones I worked on had a ceramic resister similar to GM. A few years later they went to a resistance wire that pigybacked the harness. They used a selinoid/relay that had an extra term. for bypass but some models used a bypass in the ign. switch. Coils that do not use external resisters do not have a resister built into it. They have more windings on the primary circuit thus giving it more resistance. This coil cannot cycle fast enough for high RPM multi cyl. engines so must be used only on low RPM &/or 1-2 cyl. engines.