Vehicle is overcharging

When you say it is overcharging, what is the actual voltage it is charging when the engine is running?

Take a look at this information. The ECM will target 14-15 volts and will back it down to 13.6 volts when needed. Let's start with what the voltage is and go from there. Thanks

Thank you for that information. yes, it is over charging when the engine is running and also the acid from the battery is leaking out.

Okay. Clearly we need to replace the battery but again, we need to find out the exact voltage it is charging. There is a chance that the PCM is trying to raise the voltage due to the battery so I would replace the battery due to the leaking and retest the alternator output.

Here is a guide on how to test the alternator:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Thank you so much. you're so helpful.

Thank you. You are very welcome. Please let us know what happens or if you need more help. Thanks

Thank you, I will.