Westerbeke 8.0KW - 60Hz EDT Operator's Manual page 41

ALTERNATORS TESTING/TROUBLESHOOTING
TESTING THE ALTERNATOR
ACAUTIDN:
Belor~
starling the fJ/Igine make .. _
- - - - - - - _ . -
-
certain that everyone is clear of moving parts! Keep
away from sheaves and belts during test procedures.
1.
~tart
the Engine.
2. After the engine has run for a few minutes, measure the
stuting battery voltage at the battery tenninals using a
multimeter set on DC volts.
a. If the voltage is increasing toward 14 volts, the
alternator is working.
b. If tl1e voltage remains around 12 volts, a problem
exists with either the a1termitor or ilie charging circuit;
continue with Steps 3 1hrough 6,
MEASURING
BATTERY VOLTAGE
(ENGINE RUNNING)
~~~
3. 'furn off the engine. Inspect all wiring and connections.
Ensure iliat ilie battery tenninals and the engine ground
connections are tight and clean
4. If a battery selector switch is in the charging circuit,ensure
!\lat it is on the correct setting. .
5. Check the battery voltage. If your battery is in good
condition the reading should be 12 to 13 volts.·
MEASURING
BATTERY VOLTAGE
ENGINE OFF)
TESTING THE
1. Connect the positive probe to the output terrinal Band
connect the negative probe to ground.
2. Wiggle ilie engine wiring harness while observing ilie
voltmeter. The meter should indicate the approximate
battery voltage, and should not vary. If no reading is
obtained, or if ilie reading varies, check the alternator
output circuit for loose or dirty connections or
damaged wiring.
3. Start the engine.
4. Repeat ilie same measurement, the negative probe to
ground; the positive probe to B with the engine running.
The voltage reading should be between 13.5 and 14.5
volts. If your alternator is over or under-charging, have
it repaired at a reliable service shop.
5. If the previous test reads only battery voltage at
terminal B, use the meter to measure the DC excitation
terminal. If 12 volts is not pre&ent at exciter terminal R,
inspect the wiring for breaks and poor connections.
Jump 12 volts from a 12 volt source (such as ilie
battery) and operate tl1e alternator. If the voltage output
is 13-14 volts, .. then tl1e alternatoris OK.
TESTING THE OUTPUT
CIRCUIT ENGINE RUNNING
#10 ORANGE B
TO STARTER SOU'NOU)
~
#16 VIOLET R
TO K-3 RELAY
E/!f1ines& Generators
'33