223003117 - E6021 COMPRESSOR ENGAGEMENT - FUNCTIONAL DESCRIPTION

Functional description

The compressor engagement circuit is controlled by the relay R5 housed in the engine compartment junction unit B01 . It is supplied by the direct line from the battery entering at pin 1 connector A of the junction unit and protected by fuse F19 .The coil for the relay R5 is supplied by the signal coming from the relay R9 which, in turn, receives a direct supply from battery from pin 1 connector A. The supply to the coil for the relay R9 is also direct from the battery from pin 1 connector A and is protected by fuse F18 .The relays R9 and R5 are energized by an earth signal coming from the engine management control unit M10 (pin 82 for R9 and pin 55 for R5 ). In this way the control unit M10 controls the engagement of the air conditioning compressor L20 at a voltage of 12 V through the relay R5 .

The engine management control unit M10 receives signals from the 4 stage pressure switch K10 for engaging the radiator fan:

• the operation at the first speed from pin 16;
• the operation at the second speed from pin 19;
• the engagement of the air conditioning from pin 47.