2892616 - E5020 ENGINE COOLING - Functional description (Heater)

Functional description

The supply for the fan N11 arrives directly from the battery from the line for the maxifuse B8: the fan therefore only works when it receives an earth command. The relays J30 and J31 have coils supplied by the line controlled by the ignition (15/54) protected by fuse B25. They are energized by an earth signal coming from the engine control unit M10. If the engine coolant reaches a first temperature level, the control unit M10 sends (from pin 23 of connector B) an earth signal to the fan 1st speed relay J30 which energizes the coil. The relay then sends an earth signal which, via the additional resistance O10, operates the fan N11 which rotates at the first (slow) speed. If the engine coolant reaches a higher temperature, the control unit M10 sends (from 45 of connector C) an earth signal to the fan 2nd speed relay J31 which energizes the coil. The relay then sends an earth signal directly to the fan N11 which rotates at the maximum speed.