* Faulty wiring or connections: Check all the wiring and connections between the battery, alternator, and starter motor. Make sure they are all clean, tight, and free of corrosion.
* Bad starter motor: A bad starter motor can draw too much current from the battery, preventing the alternator from properly charging it.
* Bad battery: Even though you have a new battery, it could be defective or have a bad connection. Try connecting a different battery to see if that makes a difference.
* Faulty voltage regulator: The voltage regulator controls the amount of current that flows to the battery from the alternator. If it is faulty, it can prevent the alternator from charging the battery properly.
Here are some tips for troubleshooting the charging system on your 1994 Astro:
* Check the battery voltage with a voltmeter: The voltage should be between 12.6 and 13.2 volts with the engine off.
* Start the engine and check the voltage again: The voltage should be between 13.8 and 14.4 volts with the engine running.
* If the voltage is too low, check the alternator output: Disconnect the positive battery cable and connect a voltmeter between the alternator output terminal and the ground. The voltage should be between 13.8 and 14.4 volts with the engine running.
* If the alternator is not charging, check the voltage regulator: Disconnect the voltage regulator and connect a voltmeter between the regulator output terminal and the ground. The voltage should be between 12.6 and 13.2 volts with the key in the "on" position.
If you are unable to troubleshoot the problem yourself, you should take your Astro to a qualified mechanic.
