charging light on but battery charging

323f tdvi BJ r4f4 2.0tdi +++ mazda 2 2013 1.3
title says all. We had this problem earlier but it was easy to repair. A connector on the batt minus , one wire too short and due to the tension it had broken off .
just some solder and problem fixed .Now however, the light keeps on.
question : is a reset or something needed or whatever? previous time it went out after say a minute drive.
thanks in advance.