Recently, my mother left the lights on in the car and killed the battery. After jumping, we noticed that the alternator was no longer doing its job. It would go in and out and eventually just out.

Since then, the new alternator used was tested and is in the car. However, it doesn't seem to be doing its job either.

Nothing was changed in the car and even though the wiring is old it looks just fine. I can run the car with another battery connected simultaneously and we can drive (until that battery dies too of course.) I'm getting aggravated and have no clue where to go from here.

Is there another voltage regulator in the car I'm not aware of? Does the car's cpu need reset or possibly replaced?

The only other problem the car has had is that it sometimes stalls when coming to a stop. The throttlebody has been cleaned and all fluids have been replaced in the past six months.

If a jump pack is hooked up to the car, when it is running it never gets passed 12.6v, so my guess is probably wiring. But it's 30* outside and tracing wiring without a garage sounds like the biggest pain. Is there anything else I should check before continuing? Fuses look good too.

Any guidance would be greatly appreciated! Thank you!