Abstract: A compact warning light employs LED lamps as a light source and has a lighthead configured for insertion into the reflector shells of a motor vehicle such as a sedan or SUV. The lighthead has a base and cover which define a sealed interior space surrounding the LED lamps. The base is constructed of heat conducting material and the LED lamps are secured to the base so that heat generated by the lamps is conducted away and dissipated by the base. The base may include a post for supporting a plurality of individually energized arrays of LED lamps. The cover may be optically clear, tinted or provided with facets or a surface texture.