Basically I understand that the signal generator (pick-up coils) send a signal to the igniter to turn the coils off and on which generates the power to fire the spark plugs.
What I'm failing to understand is how the pick up coil generates this signal and what amount of voltage is sent to the igniter. As one of the igniter tests calls for running a screw driver blade in front of one of the pick ups to test for spark, it must be a very weak voltage.
Also, somome pick up coils have one wire each and a common ground wire to the igniter with the more modern ones have 2 each and a seperate ground I believe (yellow/ green) that connects to the wiring harness close to the igniter. How does the two wire pick-up work? Does it send 2 signals or is it one signal into the box and back out in a loop?
I also wonder about the igniter signal to the coil. I know that the power to the coil is "on" all the time and the transistors in the igniter turn this off on receipt of the signal from the pickup coils which then causes the coil to deliver power for spark. What confuses me in my readings is references to power for the igniter. As far as I can see it is not powered but recieves voltage from the coils. Am I understanding that correctly?
What I'm trying to come to grips with is why my test igniter/signal generator from a 750 is not creating a spark. The signal generator specs out at the correct resistance, the igniter checks out in my running 750 and the coils are powered and show correct resistances. All things being equal there should be spark.
If someone could help clarify this all for me I might be able to suss out where I'm going off the track. So far all I can think of is that there is some issue in the wiring harness itself so my next step will be to try the igniter trigger test using the ohm meter and if that doesn't show anything then I'll wire the out pins directly to the coils and bypass the harness.
As always all input is greatfully appreciated. As I've often found, sometimes even the most off the cuff statement can lead to the Eureka moment so feel free to add your comments.
Cheers,
Spyug
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