as a learning moment, try the meter test on your jeep that cranked.
see the voltage at rest, try cranking it over but don't start and see what the meter reads then.
you will see the recovery of voltage is almost instant and rest voltage is much higher.

this is why I said the battery instead of the other items called out.
not that they couldn't be an issue, but once you establish battery voltage that low, you should start to verify the battery is good before moving further away.