Resistor

imacrazy

Senior Member
With a 12 volt system, using a 6 volt coil
without a resistor. Will that cause the engine
to cut out at times? I rebuilt distributer and
changed carbs. I guess it could be plugs, but they
are not to old.
 
Yes, it puts twice the load on the points and coil, so the points may burn and the coil will overheat. You can buy a ballast at any car parts store.
 
6V coils are actually 8V coils, but unsuitable for 12V operation. Use the dropping resistor or better yet, get a 12V coil such as a Pertronix 40611 coil with a 12V primary & 40,000 volt secondary.
 
All the more reason to stick to a 6 VOLT system. ON 6 VOLT, by upshifting, I once CRANKED Minerva a HALF BLOCK, to Bad Buds' Gas Station!!---She went like a "HYBRID"!!
Bill W.
 
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With a 12 volt system, using a 6 volt coil
without a resistor. Will that cause the engine
to cut out at times? I rebuilt distributer and
changed carbs. I guess it could be plugs, but they
are not to old.

Yup, will burn it up...eventually with the points. You can get/use the ceramic resistor that was used in the 50s. You can also use a special resistor wire in ceramic place. Looks better, IMO.
Oh, and a third option is to buy a coil with the resistor built right into coil. I use this option and am running same one for 10 yrs now :)
 
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FWIW:

1. After reading countless messages on vintage vehicle Forums, some Model A owners may assume it to be a "requirement" to change to a 12 volts system, especially from a more powerful engine cranking standpoint.

2. It may help for some new Model A owners to realize that "huge" cars such as large (4) door 1955 Chryslers and many others, had an original 6 volt electrical system that worked great and cranked great with a V-8 engine that looked about the size of at least four (4) Model A engines.

3. Others may have different and other opinions for changing to 12 volts; however, this is just to remind someone that the Model A 6 volt electrical systems can work just fine in many cases.

4. One main reason mentioned often to switch to 12 volts includes if one is wanting to air-condition a Model A.
 
In the end the Model A was made with a 6V system. If owner's choose to keep their cars as origianl as possible, they will likely benefit from the fact that there are many more folks here that know Model A as the came off the assembly line. As you change from the original, you're making your car a one off one of a kind. Before a major change from the original, one should consider that. To each owner their own as they know best.
 
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