Spitfire Bit confused by my Spitfire coil wiring...

[Lionheart]

My 77 spitfire has a magnetic pickup in the distributor. The two wires coming out of it are red and black. These wires go to the distributor + and - terminals.

Is this the right wiring? The car runs, but this connection doesn't seem right to me.

 

[DougF]

It would be correct. Otherwise, you would be replacing your ei unit. Pertronix(I assume that is what you have) will burn out immediately if the wires are crossed. Also, make sure that those two wires do not rub on the distributor shaft. They don't run very long before the insulation wears away and your ei is trash.

 

[Lionheart]

I don't have a pertronix (although it may work the same way)...I have the stock dizzy with the electronic pickup in lieu of points...77 model year.

I think what's confusing me is that it appears that the electronic breaker would be shorting across the primary leads of the coil.

The more I think about it, the breaker is probably just pulsing the (-) side of the coil to earth ground inside the dizzy. Whereas the red wire would just be supplying operating volts to the breaker.

Does that sound right?

 

[guzzul]

The two leads coming off the pickup inside the distributor do not connect to the coil. This pickup is itself just a small magnetic coil. When one of the little bars in the reluctor, which is mounted on the dizzy shaft, pass the pickup, this generates a small voltage within the pickup that triggers a transistor inside the amplifier unit.

The transistor in turn makes and breaks the coil primary circuit.

If its working, its connected properly.

 

[Lionheart]

The two leads coming off the pickup inside the distributor do not connect to the coil. This pickup is itself just a small magnetic coil. When one of the little bars in the reluctor, which is mounted on the dizzy shaft, pass the pickup, this generates a small voltage within the pickup that triggers a transistor inside the amplifier unit.

I don't have an amplifier.
The pickup wires go directly to the coil primary (red > +) (black > -).

It runs. Perhaps I'll just leave it at that for now.

Thanks,
Len

 

[Scott_Hower]

Are you sure someone didn't fit an Ignitor? It connects just as you describe.

 

[guzzul]

Len - if it looks like the attached inside the dizzy, then as Scott and Doug have said, its a Pertronix Ignitor, or something very similar, not the original Lucas.

The Ignitor red wire is supposed to go to the the + terminal of the coil.

Check out the following link:
https://www.pertronix.com/downloads/ignitor12vneg.pdf

 

[Lionheart]

Yeah, it looks similar to that, and I noticed a sticker on the side that says "IGNITOR". Must be as you say...thanks so much for clarifying that for me.

 

[Lionheart]

Excuse the Columbo re-attack, but ahhh..."Just one more question".

Is this system with the ignitor meant to have a capacitor (condensor) in the circuit? If so, would that be from coil (-) to earth?

 

[guzzul]

No, it should not be part of the Pertronix ignition.

What you might be referring to is a small (often blue-coating) capacitor that is mounted on coil. That's for noise suppression (i.e. radio interference). Usually a 1 microfarad capacitor. It should be mounted on the igintion-switch side of the coil (i.e. the + side), and go from the coil push-on to ground.

I don't think it would be a problem on the negative side of the coil, but I don't know as it would work there.

 

[Lionheart]

Yes, that's the one I was looking at. Nice to get such a definitive answer...much appreciated.

Len