The relay R05 for the engine compartment junction unit B001 controls the circuit for engaging the compressor L020.The supply line (+30) for the compressor is protected by fuse F19 of the engine compartment junction unit B001 via relay R05.The earth signal used for energizing the coil for relay R05 arrives from pin 29 of connector A of the engine management control unit M010.The climate control system control unit M070 sends a signal, from pin 8 of connector A, for enabling the engagement of the compressor, to the engine management control unit M010 (pin 54 of connector A).Depending on its internal control logic, the engine management control unit M010 sends the command (pin 72 of connector A) for enabling the relay R09 which, in turn, provides a supply at the other end of the coil for the relay R05 which allows the engagement of the compressor L020.Linear sensor K120 is connected to control unit M010 at pins 22 e 12 of connector A for power supply and earth and pin 13 for transmission of its own signal.The climate control system control unit M070 receives a supply (pin 16 of connector D) from the line from the battery (+30) protected by fuse F39 of the junction unit under the dashboard B002 and from the line controlled by the ignition (INT) via fuse F49 of B002 (pin 10 of connector A).