poopsandwich

So I just got this Acura TL and I am super new to working on cars. The car used to run and had a worn-out tensioner which was shaking which I was planning to fix but eventually, another problem came up: the car stopped starting. There was no crank, no lights on the dash, nothing except the tail lights would turn on. The alternator and starter were replaced about 2 months ago and I tried to boost the battery and use a whole other battery but the same result came up. The battery terminals are pretty rusted up but Idk if its that, and the alternator I replaced it with was pretty old too but if it was the alternator the lights would still turn on no? Anyway, I have no idea what's wrong anymore so it's just sitting and I would appreciate any kind of advice.

poopsandwich

forgot to mention that the car is a 2008 Acura tl type s