In my experience, the starter solenoid releases a huge spike when ignition switch goes from crank to run. An original starter solenoid post, is typically a 3 foot tap from battery terminal, perhaps #8 cable. Dart67 has a much better solution.
In my car, it's maybe 18" of #2 from the battery to the starter solenoid. So that voltage spike is totally localized and is not sensed anywhere else along that 18" of #2? Just at the solenoid and then is somehow attenuated in a very aggressive, exponential fashion, so as to be totally gone 18" of battery cable away? Just wondering. Thanks.
