The relays
T6
and
T7
in
the engine compartment unit B1 manage the switching on of the fan
N11
at two speeds: their coils are supplied by the ignition-controlled
line (15/54), while the power lines are protected by the 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
.
If the engine coolant reaches a first temperature
level, the control unit
M10 sends a signal from pin 90 of connector
A to the fan 1st speed relay T6 which then sends a supply, via the
additional resistance O10, which operates the fan N11 which rotates
at the first speed (slow).
If the coolant reaches a higher temperature
level, the control unit
M10 sends a signal - from pin 30 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.