The supply for the fan
N11
arrives
directly from the battery from the line for the VENT maxifuse of
B6
:
the fan therefore works when it receives an earth command.
The relays
J30
and
J31
, specific
to the cooling system, receive a supply at their coils from 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 the first
temperature stage, or the 4 stage pressure switch
K10
(pin
3) signals to the control unit
M10
(pin 44) that the first
pressure stage has been reached, then the control unit
M10
sends
an earth signal (from pin 26) to the 1st speed fan relay
J30
which
energizes the coil. The relay then sends an earth signal which,
via the additional resistor
O10
, operates the fan
N11
which
rotates at the first (slow) speed.
If the engine coolant reaches a higher temperature
or the 4-stage pressure switch K10 (pin 6) signals to the control
unit
M10
(pin 43) that a higher pressure stage has been reached,
the control unit
M10
sends (from pin 25) an earth signal
to the 2nd speed fan relay
J31
which energizes the coil.
The relay then sends an earth signal directly to the fan
N11
which
rotates at the maximum speed.