223003143 - 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 the battery from pin 1 connector A. The supply to the relay R9 coil is controlled by the ignition and arrives via a line protected by fuse F16 .The relays R9 and R5 are energized by an earth signal coming from the engine management control unit M10 connector B (pin 6 for R9 and pin 12 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 connector B receives signals from the 4 stage pressure switch K10 for engaging the radiator fan:

• the operation at the first speed from pin 28;
• the operation at the second speed from pin 38;
• the engagement of the air conditioning from pin 27.