new battery yeterday light saying charge system on 1990 Lincoln Town Car

car sputters after driving 15 min then stalls its an 86

Asked by for the 1990 Lincoln Town Car
You likely have an alternator or voltage regulator problem. You need to see how many amps and volts are present in your charging system. Start by getting your battery charged, and then have a good test to your charging system to confirm your failure. Good luck.