Resistor Info

6v to 12v conversions - Resistor(s) needed:

Depending on your setup, you could need any 1 or 2 of 3 possible resistor(s):

  1. There is the infamous OEM ballast resistor part number: A8NN 12250B Resistor And Mounting Block Assembly 1939-47
  2. A8NN 12250A Resistor And Mounting Block Assembly 1948-50
  3. The 12 to 6v dropping resistor part number: 8NE 10306 Resistor (Used To Reduce 12 Volt To 6 Volt)

And a current limiting resistor 'trick', which is merely a 2-pack of Radio Shack 1-ohm 10-watt resistors twisted together piggyback (in parallel) to make a 1/2-ohm 20-watt resistor.

What you need depends on what you have as electrical equipment, and your system voltage. For instance, if you have a 12v conversion: If you have a real 12v side mount round can coil. you don't need anything. If you have a newer 12v front mount coil, use the 'trick' resistor mentioned above. If you have a 6v side mount round can coil, use the "12to6" dropping resistor. If you have a front mount square 6v coil, you will need both the "12 to 6v" dropping resistor and the appropriate ballast resistor. If you need more info, let us know, post a question in the N-forum. Also, if you have a side mount round can coil, make sure you hook the polarity up correctly, otherwise you will loose some spark energy. On your 12v. if it is an alternator it is most likely negative ground. If it is a generator, it could be either. Some round can coils are marked +/-, some are marked bat/distributor (think of bat as negative and distributor as positive for the OEM setup.) Hook up accordingly - distributor is ground.(via points). So, if it is negative ground, hook '-' or dist to distributor, and hook up '+' or bat to the ignition wire from your dash. If a front mount coil, don't worry about it as it is hardwired anyway and you can't really change it.

 

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