Stalls out instantly and turns off all lights

Good morning.

Low battery voltage is usually the issue.

I would check the battery cables to be sure they are clean and tight.

I would also check the charging system to be sure it is working correctly.

Roy

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

https://www.2carpros.com/articles/car-battery-load-test

https://www.2carpros.com/articles/how-to-check-a-car-alternator

I was hoping for a more advanced answer. I suppose more details would have helped on my part. The battery and alternator are new. Battery terminals are also new. Car cranks over within two or three seconds when working. When issue occurs, car goes from running to an instant shut off. No dimming of lights or gauges, just running, and then off when lights are turned on, brakes are pressed, or car is put into drive. Battery voltage is correct before, during, and after issue. No corrosion on cables, posts, or terminals. When car actually starts, it can be started and driven for several days with no issues. Hope that helps

It sounds like you are losing all electrical power.

That comes from either the battery terminals or a connection somewhere. Chevrolet used a wire that went through the firewall junction block to feed all the inside of the car. That included the ignition switch which will control the running of the motor.

Remove the junction block and make sure all the wires are clean, tight and not burned.

Roy

Thank you for your help. I will check that and will get back with you. I appreciate your help immensely. I know it is difficult to troubleshoot from a computer and to go off limited information. So thank you again.

You are welcome.

Roy