ballast resister placement

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rick 48 cub
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ballast resister placement

Postby rick 48 cub » Wed Apr 29, 2015 9:44 am


Do you think it makes any difference installing the ballast resistor between the coil and distributor instead of on the plus side of the coil as shown in schematics?

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Re: ballast resister placement

Postby staninlowerAL » Wed Apr 29, 2015 3:37 pm

In the diagram the reason that the resistor is on the + side (input) of the coil is the coil shown is 6v. If you power a 6v coil with 12v battery without the ballast resistor, you are going to fry the coil and probably the points. The resistor steps the voltage down to prevent that. If you use a 12v coil with internal resistor you can do away with the external ballast resistor. The reason for the diagram showing + on the input side of the coil is you have changed the generator out and replaced it with the 12v alternator and changed the battery from pos ground to neg ground.

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Re: ballast resister placement

Postby Bus Driver » Wed Apr 29, 2015 8:44 pm

The resistor in the primary wire between the coil and distributor will be fine. But probably more difficult to mount.
Last edited by Bus Driver on Thu Apr 30, 2015 7:21 am, edited 1 time in total.
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Re: ballast resister placement

Postby Boss Hog » Wed Apr 29, 2015 8:55 pm

I find it better to replace the coil with a 12 volt with internal resister. It will last longer and you eliminate 2 more connections to deal with as well as the resister , that I think are problematic to begin with.
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Re: ballast resister placement

Postby Gary Dotson » Thu Apr 30, 2015 7:18 am

It makes no difference which side of the coil the resister is wired into. It serves the same purpose, that being to reduce current flow.

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