Stalls out instantly and turns off all lights

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

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.