battery light on have replaced fuses and checked alternator for charging

So I recently purchased a 91 integra for 300$ thought it would be a fun car to mod. Anways it runs fine when it’s jumped or I swap the battery but even when I swap the old battery with the one I know for sure is good the battery light stays on. I’ve swapped the old blown battery fuse in the engine bay and I’ve checked the alternator solenoid fuse under the dash and still nothing I’ve checked to make sure the alternator charges the battery with a multi-meter it reads 14 volts when I checked it and I’ve ran the negative battery terminal through the multi meter to the battery post and it doesn’t read any amps when it’s off so there’s no drain in the battery. So does anyone have any ideas? Last bet for me is to swap grounds and battery terminals, although the other battery starts the car up fine but the battery light still stays on

going to bump this once but I’m suspecting the alternator anyone know where the wire is that goes out from the alternator?