My battery light is flashing and I a new battery on 1999 Ford Taurus

and the next day I got new plug/clip put on alternator and the battery light still flashing

Asked by for the 1999 Ford Taurus
have alt tested it may not be charging
the alt was going up to 13.96 after the plug on it was redone
thats not bad ck grd wires at battery and eng block. it still could be an intermitent regulator issue inside alt