223002783 - E5020 ENGINE COOLING - FUNCTIONAL DESCRIPTION (MY 2005)

The power supply for the fan N11 arrives directly from the battery via relays R6 and R7 housed in the engine compartment junction unit B01 through the line entering pin 1 connector A of the actual junction unit.The power supply for the relays is protected by fuses F7 for relay R7 and F6 for relay R6.They are energized by two distinct earth signal coming from the engine management control unit M10.The engine temperature sensor K36 measurs the temperature of the engine coolant and, if the values of this parameter are high, the control unit M10 sends an earth signal from pin 90 of connector A to the relay R6 (which manages the first fan speed) which energizes the coil. The relay R6 thens sends the power supply, via the resistance O10, activating the fan N11 at the first speed (slow).If the engine coolant reaches a higher temperature level, the control unit M10 sends an earth signal from pin 69 of connector A to the relay R7 which controls the second fan N11 speed making it turn at the maximum speed.