a method for manufacturing an indicator module for an exterior rearview mirror assembly for a vehicle includes providing a hollow housing formed by injection molding of plastic material and providing a circuit board having a first side and a second side opposite the first side , with at least one light emitting diode disposed at the first side of the circuit board . the circuit board is disposed between a rear end and a front end of the housing such that the first side of the circuit board faces the front end of the housing . with the circuit board disposed between the rear and front ends of the housing , potting material is disposed at and over the second side of the circuit board to seal the rear side of the circuit board . a diffuser element is attached at the front end of the housing and closes the front end of the housing .