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Electronic Ignition 1979 EI DIZZY in Datsun 510 L20b


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Hey I was wondering if you can burn out your ignition unit by accidentally switching B and C when hooking it up? Could trying to start the engine like this cause it to simply burn out? I just finished building my engine and I am not getting spark so I suspect this may be the prob cause everything is at top dead center, the oil pump drive is at 11/28ths position and my rotor is pointing to my number one plug wire.

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All ignition systems work basically the same way. Power is applied to a coil, and a switch grounds the coil, and when it is time for a spark to happen, the switch opens. The switch could be a set of points, A GM HEI module, A transistor buried in a computer somewhere, or the matchbox, or many other possibilities I have not mentioned.


Swapping the connection to the "B" and "C" terminal applied power directly to the "switch" in the matchbox without the resistance of the coil to limit the current flow. This could very easily blow out the "switch" in the matchbox, especially if you tried to start the engine.

However, I think the "matchbox" does not turn on until the rotor is turned. It may be OK.


This is how to test a matchbox distributor out of a car.



I did not lay everything out very carefully, so all the wire connection can not be seen, so I will tell you what wires are hooked up and where.

Positive from a 12 volt battery, goes to coil positive, and the "B" terminal on the matchbox.

Coil negative goes to the "C" terminal on the matchbox.

Spark tester ground goes to the body of the distributor. You can use an old spark plug, but the spark tester I can set to a wide gap. The other end of the spark tester goes to high voltage out from the coil.

The body of the distributor goes to battery minus. Make this connection last. Once you made this connection, the ignition system is live.


Put one hand behind your back, and spin the distributor shaft. It should spark like mine did in the short video.

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