The supply for the fan N11 arrives directly from the battery via relays R6 and R7 housed in the engine compartment junction unit B01 from the line entering pin 1 connector A of the actual junction unit.The supply for the relays is protected by fuse F7 for relay R7 and fuse F6 for relay R6 .They are energized by an earth signal coming from the engine control unit M10 .The engine temperature sensor K45 measures the temperature of the engine coolant and, if the values for this parameter are high, the control unit M10 sends an earth signal from pin 20 of connector B to the relay R6 (which manages the first fan speed) which energizes the coil. The relay R6 then sends the supply, through the resistance O10 , operating the fan N11 at the first speed (slow).The high pressure in the climate control system, measured by the 4 stage pressure switch, determines the switching on of the second speed ( See E6021 COMPRESSOR ENGAGEMENT).If the engine coolant reaches a higher temperature, the control unit M10 sends an earth signal from pin 19 of connector B to the relay R7 which controls the second fan N11 speed which turns at maximum speed.This signal comes out of pin A connector C of the engine compartment junction unit B01 .