Ignition issue

MadScientistMat said

Stock Mopar modules weren't very sophisticated - they ground the coil by default and briefly un-ground it in response to a pulse from the distributor. It's possible some variants wait to ground the coil until the first pulse arrives, but if the car had one of those, you'd be seeing 12v at the coil negative terminal.

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I did some testing... and I was wrong how the ECU works (i'll update my earlier post)

I got 1 v on the neg side and less than 12 V (started off at 11 then quickly dropped to 5 as the ballast heated up) on the positive side with key in the run position. I concede that the ECU grounds the coil continuously when powered up.

INTRESTINGLY... with the negative lead off the coil it had 4.5 K ohms with no power to the ECU and 22 M ohms with power to the ECU between the negative lead and ground and 0.1V . So it looks like the coil itself adds to the ECUs circuitry and causes the transistor to switch on making the ground.

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