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Electrical
Electrical system
system
10
10.1
.15.
5.7
7 Pu
Pump
mp m
mot
otor
or
The pump motor's speed
The pump motor's speed gradually drops.
gradually drops.
(High temperature on the pump
(High temperature on the pump regulator)
regulator)
Was the warning text “High tmp
Was the warning text “High tmp
hydrau C” visible on the display when
hydrau C” visible on the display when
the symptom occurred?
the symptom occurred?
šš
No
No
Go to the next page, high pump motor
Go to the next page, high pump motor
temperature.
temperature.
Y
Yes
es
Check that the regulator fan works as it
Check that the regulator fan works as it
should by first removing the battery
should by first removing the battery
plug and then restarting the truck
plug and then restarting the truck
again.
again.
Does the fan start within about 20
Does the fan start within about 20
seconds?
seconds?
Y
Yes
es
Check that nothing obstructs the air
Check that nothing obstructs the air
flow through the regulator's heatsinks.
flow through the regulator's heatsinks.
If the heatsinks are covered in dust or
If the heatsinks are covered in dust or
other objects, clean under these.
other objects, clean under these.
No
No
Connect a voltmeter and repeat the
Connect a voltmeter and repeat the
procedure to check the regulator fan.
procedure to check the regulator fan.
Is the voltage at least B+ 48V for a few
Is the voltage at least B+ 48V for a few
seconds after the fan has started?
seconds after the fan has started?
Y
Yes
es
Change the fan.
Change the fan.
No
No
Is there B+ 48V on the fan?
Is there B+ 48V on the fan?
šš
No
No
Check the cables between the fan
Check the cables between the fan
contact X26.1 and
contact X26.1 and the A
the ATC contact
TC contact
XC5.19 carefully. If the cables are OK
XC5.19 carefully. If the cables are OK
and the truck has no other faults,
and the truck has no other faults,
change the
change the A
ATC.
TC.
Y
Yes
es
Check the cables between the fan
Check the cables between the fan
contact X26.2 a
contact X26.2 and the A
nd the ATC contact
TC contact
XC5.12 carefully. If the cables are OK
XC5.12 carefully. If the cables are OK
and the truck has no other faults,
and the truck has no other faults,
change the
change the A
ATC.
TC.
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