[Corley]

Sure sounds like a good theory to me. Good deal scoping it, I hope before installing the new one. Some other ideas, an inductor in serries with the coil, a cap accross the coil feed, a relay feeding only the coil direct from the battery, a ballast resister to the coil only, with one of the previous noise filters, a diode to ground to short out the spike, bow to the east before shutting it down, more prayers, etc. Maybe a different brand module would be more counter emf proof. Of course, you will move everything else from that ckt.
Sounds like you are on the right track. Mine is still working a treat, so I'm sure you will conqure the issue.

To the best of my knowledge, no one else has reported any issues like yours. I admire your persistence!