Hi,
Are you certain the battery is good? If you have a voltmeter or multimeter, check to see the voltage at the battery. Also, make sure the terminals are clean and tight. It isn't uncommon for a loose or corroded connection to do what you are experiencing.
Take a look through this link:
https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked
We need to start at the source, the battery, and move from there. Let me know what size engine is in the vehicle. It could be a 2.4L, 3.5L, or a 3.6L. If you find no issues with the battery, I can start looking through wiring schematics to see where there could be a loss of power.
Also, let me know if anything works. For example, the brake lights, headlamps, horn, and anything you can think of that is electric.
Take care,
Joe
Tuesday, August 17th, 2021 AT 4:21 PM