Underground cables are vulnerable to a variety of issues due to subsurface settings, wear and tear, rats, and other factors. It is difficult to diagnose the source of the fault, and to examine and correct issues, the entire cable must be removed from the ground. Using an Arduino, the project effort aims to determine the location of a fault in subterranean cable lines from the base station in kilometres. The wire must be examined for defects in order to discover a fault. This prototype employs the concept of Ohms law. The current would fluctuate depending on the fault length of the cable. The suggested method pinpoints the fault's exact location. To ensure correctness, the prototype is built with a series of resistors that indicate cable length in kilometres, and faults are created by a set of switches at every known distance. KEYWORDS : NODE MCU module, cable fault, Arduino, switches