A LED lamp mounting assembly for use in motor vehicle lamps is described. The LED lamp mounting assembly connects a LED lamp to a pre-existing incandescent lamp socket in a motor vehicle. The LED lamp mounting assembly therefore allows a LED lamp to be operated from incandescent lamp hardware. In one embodiment, the LED lamp mounting assembled includes a LED lamp assembly, a heat sink, a cradle, printed circuit boards and an electrical connector. The electrical connector is insertable into the incandescent lamp socket and connects to the printed circuit boards. The printed circuit boards power the LED lamp assembly and the heat sink adsorbs excess heat created by the LED lamp assembly. The motor vehicle lamp becomes a LED lamp without any changes to the existing incandescent lamp hardware.