Abstract: The invention relates to an air conditioning system for a motor vehicle, including a cooling circuit equipped with a compressor (1) associated with a clutch (8), a condenser (2), a pressure reducer (4) and an evaporator (5). An electric circuit (22) has mounted therein, in series, a coil of the clutch (8), a pressure contact (10) for measuring the excess pressure of the cooling circuit, a pressure contact (11) for measuring the underpressure in the cooling circuit, a thermostat (13), and a shunt and detector (18, 19) for monitoring the electric continuity of the circuit. An electronic control circuit (20) controls, in case of electric interruption, an electric display component (21) mounted on the dashboard of the vehicle.