The power supply to both fans
N11
and
N12
is controlled by two relays
R7
(1. speed) and
R6
(2. speed), located in relay control unit
B3
.
Both relays are supplied with power directly
from the battery - junction unit
A5
- by a line protected
by a special fuse
F9
for
R7
and
F8
for
R6
,
all located in
B3
.
Functional description
if the coolant temperature reaches the first
temperature stage, or the 4-stage pressure switch
K10
-
pin 3 - indicates to control unit
M10
- pin 15 of connector
E - that the first pressure stage has been reached, control unit
M10
sends a signal to 1st speed relay
R7
from pin 6 of connector
A.
If the engine coolant reaches a higher temperature
level or the 4-stage pressure switch
K10
(pin 6) signals
to the control unit
M10
that a higher pressure stage has
been reached, then the control unit
M10
sends an earth signal
to the 2nd speed fan relay
R6
from pin 45 of connector C.
When 1st speed relay
R7
is excited,
it sends an earth signal through additional resistance
O10
and
012
to operate fans
N11
and
N12
simultaneously,
which turns at the first speed (slow).
When 2nd speed relay
R6
is excited,
it sends an earth signal directly to fans
N11
and
N12
,
which turn at the maximum speed.