WEICHAI WD10 Service Manual - page 138
Service Manual for WD10 Diesel Engine
128
c) High charging voltage
Fault 3: High charging voltage
Phenomenon
Fault detection
Troubleshooting
High charging
voltage reading on
voltmeter
a. Check whether
voltmeter is damaged.
b. Check whether wires,
connectors and bolts
in charging system are
loose and producing
too much heat, check
whether there is short
circuit in circuits and
generator housing.
c. Check whether the
battery can work
normally.
d. Measure output
voltage of generator
W/R/AC terminal
(should be about half
of B+ terminal
voltage).
e. The fault is still
existed after finishing
above inspections.
a. Measure generator B+ terminal voltage,
which should be within 27.8~28.4V, if the
voltage is normal, then it means voltmeter
failure and should be repaired or replaced.
b. Retighten the bad-contact parts and loose
wires, re-plug the loose connectors firmly.
If there is short circuit, reconnect the
wires.
c. Check whether the charging current drops
quickly in short time (from 50A to 10A or
lower); consider a battery replacement if
not.
Check whether battery is clean and dry,
whether its terminals and clamps are in
good condition, replace them if damaged.
d. If there is big difference between terminal
W/R/AC output voltage and normal range
and big voltage drop happened after the
engine loaded, then it means failure in
generator rectifier
bridge
or stator,
consider to repair or replace.
e. Replace generator regulator, stator or the
whole generator.
d) Unstable charging voltage
Fault 4: Unstable charging voltage
Phenomenon
Fault detection
Troubleshooting
When the engine is running
normally,
voltmeter
indicates charging, but the
pointer is always oscillating
and cannot be read (or
charging
indicator
twinkling)
a. Generator belt and relevant
pulley belts are loose.
b. Bad contact in charging
circuit.
c. Collecting ring accumulates
too much dirt, or electric
brush is severely worn, or
brush spring is weak or
broken.
d. Damaged regulator.
a. Tighten generator belt and
relevant pulley belts.
b. Check
and
fasten
all
connectors
in
charging
circuit.
c. Clean the dirt, or replace
the brush and brush spring.
d. Replace the regulator.