1999 Chevy Astro Charging system

There are a number of things that can cause this, but this is caused by a parasitic draw. Basically, there is something that is not turning off and it is draining the battery.

Here is a guide that will help with the common causes of a battery drain issue:

https://www.2carpros.com/articles/car-battery-dead-overnight

If this does not help find the issue, then we need to test this by performing a battery draw test.

This is done by putting a meter in series with the battery negative cable. This means you disconnect the negative battery cable, and you connect the red lead to the battery post and the black lead to the battery cable. Then set the meter to amps and shut the engine off and flip the latches to the front doors so that the computer thinks they are closed. Give it 10 minutes and we want to see less than 35 milliamps on the meter.

If you see more than this, remove fuses until it drops and find which system is causing the issues.

Please run through this and let me know what questions you have. Thanks