External Ballast Resistor on Coil?

[AlanH]

Bill,
If you look at the top picture for reference, then both the Green and the Green&Black wire connect to the same terminal on the coil, the + terminal.
The Green wire is the the ignition supply when the engine is cranking, and the Green&Black wire the ignition supply when the engine is running.

The - terminal will have a wire that runs down to the distributor, the thin orange wire behind the high tension lead in the picture, you can just make out a connector on the lower terminal.
If you have an electronic tachometer you will also have a (generally) white wire that also connects to the - terminal which is the pulse feed to the tachometer.

Alan.

[Bill2298]

Alan,
Thanks for your reply. I just have one wire, its green/black, from the ignition to the pos (+) terminal of the coil. And that agrees with what I see on the wire diagram, ( I think I copied that from a papajam post a few months ago).

The neg (-) terminal wire runs to the distributor.

I was wondering what was up because the blue coil I just installed was getting much hotter than the old coil (with ballast) did, and when I put my multimeter on the new blue coil, it was not reading RPM correctly, but the old coil with ballast did read RPM correctly.

I wanted to read RPM correctly on multimeter while turning the decel in/out to get the best rich/lean mixture.

I just put the old coil back.

[marcotheman]

Hi!

Just read this thread about ballast resistors. Does anybody have a Marelli Ballast resistor as mine is broken and i want to keep the ignition as original as possible?

Thanks

Marco l

[60sRacer]

The purpose of the ballast resistor was to reduce the voltage across the points, to reduce arc wear on them. The ignition in the start position provides full voltage to the points ( bypassing the resistor), and hence to the coil for start. Then in run position, the ignition voltage goes thru the resistor as a voltage drop, resulting is about 6 volts to the points and onward thru the coil. Makes the running spark weaker, but the trade off was longer points life.

If you use one of the optical or magnetic breakers in your distributor, the resistor is worse than useless. Or any of the MSD or similar electronic ignition systems.

Robert

[180OUT]

I think I'm correct in saying that the original Pertronix (and also the Hot Spark which is very similar) require a ballasted, high resistance coil. The Pertronix II and III can use low resistance, unballasted coils.

But do these prohibitions apply to a original Pertronix driven by an MSD?

[alfaparticle]

Quote:

Does anybody have a Marelli Ballast resistor as mine is broken and i want to keep the ignition as original as possible?

[marcotheman]

Hi

Yes i would like to buy it from you.
How can i go about paying for it?

Do you have a photo of it that you can show me?


Thank you

Regards

Marco

[alfaparticle]

I will send you a picture tonight. Where are you located?

[marcotheman]

Hi

I am located in England.

I am looking forward to the picture!

Thank you

Regards

Marco

[alfaparticle]

You will save shipping costs if you can find one over there. Have you tried Chris Sweetapple at Highwood Alfa? He has used parts in addition to new stuff. I will gladly ship it to England but it may cost more than it is worth.
I will post the picture this evening - East Coast US time.

[marcotheman]

Hi

Let me know of the postage costs as i really would like to buy this one off you if it is a good one.

Thank you

Regards

Marco

[alfaparticle]

Shipping is $5. Please PM me for my paypal address.
Thanks.

[marcotheman]

Hi

That looks great!!

Let me have your Paypal Account Number so i can pay you.

My home email is : marco@broadlands-guest-house.co.uk

Thank you

Marco

[marcotheman]

Hi Ed

I have paid you via paypal.

Please let me know when you have despatched it.

Thank you

Regards

Marco

[Alex]

FYI, I have a dozen of these, brand new. Sorry for the late response Marco.