At first we thought it was the battery, replaced it after we checked (it was no good even after sitting on a charger), then thinking it could be the alt, so I wanna take the belt off to check. One issue, the tension is insain. I’m not sure what I can do besides either try loosening the alt first then tension or just cut the belt, which doesn’t need to be changed.
Ion know man.
Theres a part called the belt tensioner in the serpentine belt system, keeps constant pressure on the belt while in motion,
Look up your make and model online, it will show you where it is and how to correctly remove the belt