The first thing I would recommend is to check for diagnostic trouble codes. This vehicle has an OBD1 system and doesn't require a scanner to retrieve codes. Here is a link that explains how it is done. Note: All you need is a short jumper wire or even a paper clip.
Next, I need you to check the alternator output. I realize it is new, but are we getting enough voltage to keep the battery charged? When running, you should see approximately 14+ volts at the battery.
All you need is a voltmeter or a multimeter. Follow this link and let me know what you find:
Start with this and let me know the results. If we find the alternator is working properly, then we will need to check for an electrical draw. Let me know if when the voltage drops if it eventually drains completely.
I will watch for your reply.
Wednesday, April 13th, 2022 AT 8:35 PM