I understand its the norm to have a ballast resistor between the battery and the coil.

Do i need to have one?

Now that all depends on your coil doesnt it

I have a 12V sports coil... it does not need a balast..

Most standard 6V coils recieve a 12V feed when you crank the engine... and then a 6V feed (via the balast) for "normal" engine running...


So... what coil do you have?

Depends on the coil, if it does then it should be written on the side of it.

All it for is to reduce the voltage to the coil when the engine is not cranking over or rather when it’s simply running.

When cranking the resister is bypassed giving the coil full 12v supply to ease starting by giving a stronger spark at the plug. This is because the starter motor is sucking most of the available battery power.

If you didn't fit it to a coil that needed one, then the current going through the distributor points would be too high normally and they would be quickly (within a couple of thousand miles) burnt out, even with a capacitor fitted.

A classic VW Beetles coil doesn't require a resister btw

mines a better description tegwin

[Edited on 11/8/09 by Mr Whippy]

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mines a better description tegwin

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Originally posted by speedyxjs
I understand its the norm to have a ballast resistor between the battery and the coil.

Do i need to have one?

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Its points.

I think its a 12v but il check later.

Cheers guys

Ballast coil is approx 1.6 ohms, standard 12v is approx 3 ohms

Thanks russ