Abstract: The present disclosure relates to methods for fabricating electrical connectors of a waterproof connector-heat sink assembly of a LED light bar module using injection molding. The methods include matching the coefficient of thermal expansion (CTE) of injection molding materials for the connectors and heat sinks. A heat sink and conductor pins are inserted into an injection mold and the injection molding materials are injected into the injection mold. An integrated connector-heat sink assembly is formed when the injection molding materials of the connectors form a waterproof seal with the heat sink when the injection molding materials solidify. Placement of the heat sink and conductor pins inside the injection mold is controlled to ensure that adhesive bonding between the injection molding materials and the heat sink is stronger than a maximum shear force.