Abstract: An LED (light emitting diode) light bar assembly is comprised of an elongated casing having an elongated cavity of substantially U-shape cross-section. The casing has a base wall, opposed side walls and an elongated open end between the side walls. One or more elongated heat sink LED modules each having two or more LEDs and electrical component parts thereof are retained in each of the modules. The LEDs are exposed in a spaced-apart relationship in a common wall of the modules. The casing is configured to removably receive and retain one or more of the modules therein in end-to-end relationship. The casing defines in combination with the one or more modules, at least one internal channel for the passage of wiring which is non-visible exteriorly of the module. At least one end connector is detachably securable to an end of the casing for securing the casing to a support structure. The connector has an internal passage for receiving wiring from the modules retained in the casing.