Burning up coils
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Originally Posted by moxy123
How quick do they burn up after they are used.
The coils primary is designed to run at 12 volts or so with the negative terminal pulsed to ground by the ignition module to exite the secondary and generate a spark.
Some systems use 10 volt coils and use a large resistor to drop the voltage down from 12 volts while running and bypass it while starting to make up for the lower voltage while cranking.
This is general info and I do not know the specifics of that system. If this applies then even with the slightly incorrect voltage the coil should run hundreds of hours while being somewhat hotter.
Are you sure the case is not being damaged when installing the coil somehow, is it plastic or metal?
What is the voltage at the plus terminal and negative terminal with the key on but the engine not running?
What is the voltage on the plus terminal while the engine is running?
How large is the resistor that you speak of that goes to the ECU?
Are you buying them at the same place every time, maybe a batch of bad ones?
How did it fail in the first place?
The coils primary is designed to run at 12 volts or so with the negative terminal pulsed to ground by the ignition module to exite the secondary and generate a spark.
Some systems use 10 volt coils and use a large resistor to drop the voltage down from 12 volts while running and bypass it while starting to make up for the lower voltage while cranking.
This is general info and I do not know the specifics of that system. If this applies then even with the slightly incorrect voltage the coil should run hundreds of hours while being somewhat hotter.
Are you sure the case is not being damaged when installing the coil somehow, is it plastic or metal?
What is the voltage at the plus terminal and negative terminal with the key on but the engine not running?
What is the voltage on the plus terminal while the engine is running?
How large is the resistor that you speak of that goes to the ECU?
Are you buying them at the same place every time, maybe a batch of bad ones?
How did it fail in the first place?
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From: Virginia
Correction on the ECU/resistor wire. I was looking at the wrong engine wiring, the 5.8 did not go to the ecu with the resistor. The diagram shows the darkgreen/yellow going to a self test connector on your engine. The TFI module and the tach destinations are still correct. Sorry about that.
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Originally Posted by Franklin2
Correction on the ECU/resistor wire. I was looking at the wrong engine wiring, the 5.8 did not go to the ecu with the resistor.
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This is really old, but in case this happens to anyone else, I wanted to inform what the problem ended up being...
There was a bad plug wire from the coil to the distributor. The excess resistance fried the coils. Didn't see that one coming...
There was a bad plug wire from the coil to the distributor. The excess resistance fried the coils. Didn't see that one coming...
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Well, after buying an aftermarket ignition system, which I wanted either way, I figured, "Hey, why not check the resistance in the coil wire." It was horrible, though it didn't look bad. Lesson learned- electrical problems don't ALWAYS exist upstream...
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