Abstract: There is disclosed a cable test unit for use in testing multi-conductor cables containing a plurality of wire pairs. The invention includes means for supplying a constant D.C. voltage; a time-governed oscillator; a recycle pulse generator for releasing sequential pulse outputs; a connector test base having anode and cathode sides; a plurality of LEDs, each corresponding to a respective wire pair, and electrically connected to the test base; means for inhibiting induction across all wire pairs except the pair at which a pulse output from the recycle pulse generator exists; and means for recycling the pulse generator. The current flow characteristic across a given wire pair varies as a function of its structural condition as either a short, open, or crossed circuit, or a loose connection, and such characteristic is reflected in the visual appearance and behavior of the LED corresponding to that wire pair.