The invention discloses a method applicable to an electric assembly of an automotive vehicle, comprising a current acquisition step for acquiring the current circulating through at least one load and a step for processing and acting, by means of an electronic system based on one or more microprocessors, which provides the disconnection of the feed from said load and alarm signals, and which also comprises carrying out, by means of said electronic system, with a determined number of instantaneous current values or samples acquired by means of said acquisition step, the calculation of the average value thereof, the update of said average value for each new sample acquired and the calculation of a variable indicating an arc limit through the calculated average current value, the method thus being adapted proportionally to the load variations.