Charging problem

Here is some wiring for your alternator. Because the pcm has some control over the generator, check for applicable trouble codes. To check codes, yourself, at the least, you need an obd2 code reader. Some of the national brand auto stores will check codes for free, if you can get the vehicle down there.

The serpentine belt ok? Plenty of tension?

Hello,

I would check the fusible link to make sure you have a connection. Also if the alternator was not an AC Delco it probably got a defective one.

Here is a guide to help check for power

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is the alternator wiring diagram you can see the instrument cluster and PCM play a roll in the system as well.

Check out the diagrams (Below)

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken