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Is it possible the coil has failed. On My Sunny I have two wires to the positive side of the coil & one to the negative. One of the wires to the positive side is from the resistor that I have deleted, so it's not necessary, but I've hooked them up to neaten the appearance. Isn't there a pair of wires going to the distributor, could one of these be broken. Has the distributor got an earth connection. My old Navara stopped dead on me one day when the earth wire came off.

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Coil - must never be wired directly to ground/earth. The earth is switched by the distributor points or the electronic module

This is also why the coil may not show a voltage when the engine is not running. The way to check for voltage feed is Voltmeter from Coil + to Battery -

btw, Ballast Resistor has nothing to do with Alternator. Ballast Resistor use depends on the coil (some coils require a resistor, others are designed to be used without a resistor)

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With points, rotating the engine will change the voltage as the coil is switched on/off. But with electronic ignition, it depends on how the unit works. The factory service manual for it will provide test procedures, example it's the Bosch/Bluebird EI unit


Quote:
1. Tacho wire disconnected from coil will read one thing
2. Tacho wire connected to coil will read the same as the coil terminal, which is various depending on how the module works. With engine off, perhaps Ground (briefly) followed by 12V via the coil winding (which will not repeat). With engine cranking, something like 9V average as it switches on/off

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