My grandson has a 2003 Eclipse automatic. The Battery/Charging light came on and he did not say anything so it eventually died after being parked. Now the transmission has locked up, button will not push in to shift and it says on the dash that it is in Reverse even though it looks like it’s in Park. The battery tests out good, but I don’t know how we can test the alternator without removing it. It makes no sound at all when trying to start, what do we do?