Lights Out No Start

FE_rex said:

Most DC motors are dead shorts when not spinning. Spinning actaully generates a reverse voltage which limits current. ...

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The peak current - is always going to be the initial current - before it actually starts moving - as it overcomes initial mechanical resistance as well as this pehenomenon
(an engine always pretty much stops on a compression stroke since that is where the most resistance is when crank is no longer being driven)
And we all know that it takes more force to initiate a movement than to sustain it.
So peak current through the starter circuit is ALWAYS going to be at the very instant it throws the solenoid
I would suggest that again, by fundamentals, if the voltage is lower, then that initial current must also be lower (to the point of being insufficient to have it actually rotate at all)

From diagnosing problems with my very first KeyLess controller systems to Rocket owners, I discovered the battery voltage on a Rocket as the solenoid first throws actually drops below 8V!!! (hard to see on a DVM it happens so quickly)
I had to change one of my devices to operate down to below 6V (the ones had been using were spec'd to 8V min and these were dropping out)

Low voltage (low enough to slowly turn or stall starter) kills starter relay contacts by having them chatter with peak or near peak current. Most 12v vehicle starter system are in no way even rated for near peak or locked rotor current service. A few contact hits at those high currents produces enough arc to pit contacts. Pits increase resistance across contacts.

It’s one thing to close contact, heavy load, light load and release vs. close then release under heavy load

Sometimes you just can't beat an old analog volt meter!