So my battery light came on. I put a multimeter to the battery, it showed just over 12.5v not running and just under with the car running. I disconnected the negative battery cable and the car died. I don’t have the money right now for a new alternator so I went to the local you-yank-it lot and grabbed an alternator. After the install…same issue. So did I get a dud alt or could there be another issue? I checked the under dash fuse box and the 10amp fuse is fine. Battery cables and terminals appear fine as well. Ideas? Tyia