This invention discloses a wiring harness, a method of manufacturing said wiring harness, and a lamp assembly which utilizes said wiring harness. The wiring harness is comprised of a plurality of insulated conductive electrical wires which extend through a modular connector plug. The modular connector plug is comprised of a molded wire matrix and a mounting plug. To manufacture the wiring harness, a molded wire matrix is overmolded onto a plurality of insulated conductive electrical wires and then a mounting plug is overmolded onto the wire matrix.