Westerbeke 5.5KW EDC 60HZ Operator's Manual page 38

ALTERNATORS TESTING/TROUBLESHOOTING
TESTING THE ALTERNATOR
A
CAUTION:
Before starting the engine 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
starting 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 the voltage remains around 12 volts, a problem
exists with either the alternator or the charging circuit;
continue with Steps 3 through 6L
MEASUmNG
BATTERY VOLTAGE
(ENGINE RUNNING)
3. Tum otT the engine. Inspect all wiring and connections.
Ensure that the battery teoninals and the engine ground
connections are tight and clean
4. If a battery selector switch is in the charging circuit,ensure
t\1at it is on the correct setting.
S. 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 OUTPUT CIRCUIT
1. Connect the positiye probe to the output teoninal B and
connect the negative probe to ground.
2.
Wiggle the engine wiring harness while observing the
voltmeter. The meter should indicate the approximate
battery voltage, and should not vary.
If
no reading is
obtained, or if the reading varies, check the alternator
output circuit for loose or dirty connections or
damaged wiring.
3. Start the engine.
4. Repeat the 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
repru,red at a reliable service shop.
S. 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
pr~ent
at exciter teoninal R,
inspect the wiring for breaks and poor lZonnections.
JunlP
12
volts from a
12
volt source (such as the
battery) and operate the alternator. If the voltage output
is
13-14
v?lts, .. then the alternatoris OK.
TESTING THE OUTPUT
CIRCUIT ENGINE RUNNING
#16 VUJLEIR
TO K-3 RELAY
Tl=R:MINAIR
Engines & Generators
32