The supply for the fans N11 and N12 arrives directly from the battery via relays R6 and R7 housed in the engine compartment junction unit B01 from the line entering at pin 1 connector A of the actual unit.The supply for the relays is protected by fuse F7 for relay R7 and fuse F6 for relay R6 .They are energized by two distinct earth signals coming from the engine management 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 connector B to the relay R6 (which manages the first fan speed) which energizes the coil. The relay R6 sends the supply, activating the fans N11 and N12 , in series from the remote control switch J39 at first speed (slow).The high pressure in the climate control system, measured by the 4 stage pressure switch See E6021 COMPRESSOR ENGAGEMENTor the high temperature of the engine coolant, determines the switching on of the second fan speed.In this case the control unit M10 sends an earth signal from pin 19 connector B simulataneously to the relay R7 and to the remote control switch J39 which has a parallel supply for the fans N11 and N12 thereby controlling the second rotation speed.