2002 Chevy Astro 02 Chevy Astro will not start

Are you saying the starter won't crank? With everything turned off, I'd use a voltmeter, dmm, whatever and take a reading across the battery posts. Make sure all the battery cables are clean on both ends.

When you turn the key to crank can you tell if there is a load on the starter circuit, will the dome lite dim, when you turn the key to crank? If there is no load on the starter circuit, it could be a neutral switch, if this is an automatic, you can't be sure without doing some testing.

You could do some testing at the starter relay in the power distribution center under the hood. Just pull the relay, have a helper turn the key to crank, use a testlite, I don't have the diagram in front of me, but, I believe there should be two hot terminals. Any testing, make sure the tranny is in park or neutral and the brake is set.