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Discussion Starter · #1 ·
Sorry guys but my coil stopped working. I had an MSD coil on and it literally melted,.. the clear yellow goo/sealant was dripping off the coil onto my wires. So I tried a stock coil I have and it isnt making spark and I couldnt find much in the FSM, maybe i just looked in the wrong place.
I was just hoping to find out,
Does the coil make spark the entire time it is supplied power? Or does the coil have a signal wire telling it to spark??

Whats hot, whats not, what makes signal? Also about the ICM,..?

Im hoping I can figure out the issue after I find out what voltage to expect from what wire.

Thanks for any help,
ZACH
 

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For a coil to make spark there has to be a fall in the field to trigger the release of stored energy. To simplify,that's what the ingition module is doing (like points in an old system) It breaks the circuit and it allows the stored charge to empty through the distribtor (optispark) and on to the plugs.

It's why ignition modules are such a pain in the butt. If the module isn't functioning properly, the signal is not passed on. They are prone to heat failure. The good news is that on an optispark, the module is not buried in the distributor at the back of a hot engine, under a long cowl just above hot headers. In your case on a meltdown, I'd think more of a short in the windings of the coil created the meltdown heat.
 

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Discussion Starter · #4 ·
Im getting no power from B5 on the BLACK connector to the PCM. I should have power coming from there to the ICM correct?

Thanks for the in-depth and explanative answers.
ZACH
 

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pulling the plug from the ICM you should have the reading at the plug:

C=(V+)A=(Pulse V+)D=(-)B(v+)

Just pull the plug turn on the ignition you should get voltage at the two outer ends and in the middle you will get ground and a pulse voltage while the engine is cranking (middle means you could be holding the plug correctly or upside down). Either way look for the voltage on the outer and the pulse on one of the middle plugs.

HTH
 
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