A system and method for identifying an electrical noise propagation path through an object, such as an automotive vehicle, from a source of periodic electrical noise. An electrical noise sensor is positioned at a selected area on the object which generates an output signal representative of the magnitude of the electrical noise. A trigger generator generates a trigger signal in synchronism with a source of periodic electrical noise and that trigger signal is connected as an input signal to measurement equipment connected to the sensor to initiate electrical noise reading by the sensor. A recorder then records the output from the sensor. The electrical noise sensor is moved to different areas on the object to determine the electrical noise propagation path.