Abstract: A tester for conductors in a multiconductor cable which afford identification of the respective ends of each pair and tests each pair for shorts and opens. A transmitter unit for connection to one terminus of the cable and a receiver unit for connection to the opposite terminus of the cable. The transmitter has a plurality of integrated circuits forming a sequencer to apply in sequence a test signal to one end of each of the conductors. The transmitter has a power supply and there is a connection over a conductive path independent of the cable to connect the power supply to the receiver whereby the receiver is extremely compact. The receiver contains a plurality of light emitting diodes that constitute signal detectors, there being one detector for each conductor. The transmitter is supplied with controls for controlling the mode of operation of the equipment and for affording variation in the number of conductors that can be tested.