A passive neutral fault current detection device fastened to cable television equipment detects the presence of a neutral fault within a subscriber's premises when the outer conductor of the coaxial cable is electrically bonded to the neutral conductor of the premises electrical service ground. In one example, the passive neutral fault current detection device employs a transformer circuit. The braided outer conductor of the coax cable acts as the primary coil of the transformer, and windings surrounding the coax cable act as a secondary coil. The windings are connected to an alert device to complete the circuit. As alternating current from a neutral fault flows through the braided sheath, a varying magnetic field is generated and impinges upon the secondary winding, which induces a varying voltage in the secondary winding. The voltage can drive the alert device which, in one embodiment, is a light emitting diode (LED).