Abstract: Apparatus for illuminating the lights of an abandoned trailer having a pigtail connector which has been disconnected from a complementally formed pigtail connector on a draft vehicle and more particularly to a plug, stored on the trailer and including a plurality of electrically conductive pins aligned with, and formed complementally, to electrically conductive pins on the trailer pigtail connector to detachably couple the trailer battery to the trailer lights. Switch mechanism is provided for selectively coupling and decoupling the plurality of electrically conductive pins on the trailer pigtail connector to each other so that the trailer mounted battery can be selectively coupled in circuit to the lights when the trailer is unhitched. An electrically non-conductive yieldable housing stows the plug and the trailer pigtail connector in mating engagement on the trailer.