Intermittent electrical problems are present in our daily lives, whether it is our automobile on which a headlight turns off unexpectedly, lights that light up on the dashboard intermittently, in short, several problems that call into question the electrical installation of our vehicle. At the electronics level, the same problems can be experienced. A diagnosis with the TDR (Time Domain Reflectometry) can find the source of the problems. With this technique, a signal is sent to the defective circuit and the impedance variation is measured, which makes it possible to identify the location of an electrical problem. A handy tool when looking for an electrical problem in circuits smaller than hair.