A security system circuit for a vehicle, the security system comprising: - an electronic main control unit, - at least one electronically operated switch, which is arranged on an input line of an electric load of the vehicle, each electronically operated switch being controlled by the main control unit and being is configured to switch between: • a connected configuration, where said electronically operated switch allows electricity to flow through the input line between a main electric power source of the vehicle and the electric load, and • a cutoff configuration, where said electronically operated switch prevents electricity from circulating through the input line between the main power source and said electric load, - a safety switch, configured to be activated by a user of the vehicle, the safety switch being configured to control the main control unit, so that each electronically operated switch switches to its cutoff configuration when the safety switch is activated, characterized in that the security system further comprises: - an electronic safety control unit, which is different from the main control unit, the safety control unit being powered by the main power source, - at least one current sensor, each current sensor being is configured to detect electric current flowing through a respective input line of said electric load, and - alarm means, configured to alert a user of the vehicle, wherein the safety control unit is configured: - to change from a waiting mode to an active mode under the control of the main control unit, the safety control unit changing to the active mode when the safety switch is activated, and - to activate the alarm means when: • the safety control unit is in the active mode, and • after a predetermined first time interval from the moment the safety switch is activated, at least one current sensor detects electric current flowing through the corresponding input line. - an electronic main control unit, - at least one electronically operated switch, which is arranged on an input line of an electric load of the vehicle, each electronically operated switch being controlled by the main control unit and being is configured to switch between: • a connected configuration, where said electronically operated switch allows electricity to flow through the input line between a main electric power source of the vehicle and the electric load, and • a cutoff configuration, where said electronically operated switch prevents electricity from circulating through the input line between the main power source and said electric load, • a connected configuration, where said electronically operated switch allows electricity to flow through the input line between a main electric power source of the vehicle and the electric load, and • a cutoff configuration, where said electronically operated switch prevents electricity from circulating through the input line between the main power source and said electric load, - a safety switch, configured to be activated by a user of the vehicle, the safety switch being configured to control the main control unit, so that each electronically operated switch switches to its cutoff configuration when the safety switch is activated, - an electronic safety control unit, which is different from the main control unit, the safety control unit being powered by the main power source, - at least one current sensor, each current sensor being is configured to detect electric current flowing through a respective input line of said electric load, and - alarm means, configured to alert a user of the vehicle, - to change from a waiting mode to an active mode under the control of the main control unit, the safety control unit changing to the active mode when the safety switch is activated, and - to activate the alarm means when: • the safety control unit is in the active mode, and • after a predetermined first time interval from the moment the safety switch is activated, at least one current sensor detects electric current flowing through the corresponding input line. • the safety control unit is in the active mode, and • after a predetermined first time interval from the moment the safety switch is activated, at least one current sensor detects electric current flowing through the corresponding input line.