The relays
T6 and T7 in the engine compartment
unit B1 manage the switching on of the fan N11 at two speeds: they
are supplied by the lines protected by fuses F6 and F7, of the engine
compartment unit B1.
Both are energized by a control signal -
earth - coming from the engine control unit
M10, pins 50 and
62 of connector A, respectively.
If the engine coolant reaches a first temperature
level, or sensor
K10 indicates to the control unit M10 - pin
9 of connector A - that a certain pressure level has been reached, the
control unit M10 sends a signal - from pin 50 of connector A which
energizes the fan 1st speed relay T6, which then sends the supply
to the fan N11 via the additional resistor O10: the fan thus turns
at the first speed (slow).
If the coolant reaches a higher temperature
level, or the linear sensor
K10 indicates to the control unit
M10 - pin 41 of connector A - that a higher pressure has been reached,
the control unit M10 sends a signal - from pin 62 of connector A
- to the fan 2nd speed relay T7, which sends the supply directly
to the fan N11: the fan then turns at the maximum speed.