Battery Care - Westerbeke 12C- TWO Operator's Manual

ALTERNATORS TESTING/TROUBLESHOOTING
TESTING THE EXCITATION CIRCUIT
1. Connect the positive
(+)
multimeter probe to the
excit~tion terminal R on the alternator and the negative
(-) lead to ground.
2. Turn the battery switch
to
the on position and note
the multimeter reading. The reading should be 1.3 to
2.5 volts (see illustration).
TESTING THE
EXCiTATION
J~IRCUJT
(IGNITION
UIVl'-~il
3. If the reading is hetween .75 and 1.1 volts, the
rotor field circuit probably is shorted or wpunded.
4. If the reading is between 6.0 and 7.0 volts, the rotor
field circuit probably is open. .
5. If no reading is obtained, an open eXists in the
alternator-excitation lead or in the excitation circuit of
the regulator. Disconnect the lead from exe. terminal R.
Connect the'positive multimeter probe to the excitation
lead and the negative multimeter probe to ground.
If the multimeter now indicates an approximate battery
voltage, the voltage regulator is defective and must be
replaced. If no voltageJs indicated, check the
excitation circuit for loose or dirty connectlons or.
damaged wiring.
TERMINAL R
. TESTING THE
EXCITATION
CIRCUIT
(IGNITION ON)
(+)
CHECKING THE SERVICE BATTERY
Check the voltage of the service battery. lhis battery shOuld
have .voltage between 13 and 14 volts when the engine is
running. If not, there is a pro.b1em
in
the service battery
charging circuit. Troubleshoot.the service battery eharging
circuit ·by checking the wiring and connections, the solenoid,
isolator, battery switch, and the battery itself.
When the problem has been solved and before the alternator
. is back in operation, take the time to tighten· and clean the
terminal studs. Also clean the connecting terminals from the
wiring harness.
ALTERNATOR REPAIR
If tests indicate a failed alternator, it will need to be disas-
sembled and repaired. Any good alternator service shop can
do the job.
NIiTE:
WESTERBEKE'S service Manual has detailed
instructions for the disa"sembly and repair of their
staridard alternators.
· BATTERY CARE
The minimum recommended capacity of the battery used in
· the engine's 12 volt DC control circuit is 600 - 900 C;old
Cranking Amps (CCA).
· Review the manufacturer's recommendations lind thel).
establish a systematic maintenance schedule for·yout
engine's starting batteries and house batteries.
• Mouitor your voltmeter for proper charging during
engine operation.
• Check the electrolyte level and specific gravity with a
hydrometer.
• Use ouly distilled water to bring electrolytes to a proper
level.
•. Make certain that battery cable connections are clean and
tight to the battery posts (and to your engine).
• Keep your batteries clean and free of corrosion.
A
CAUTION:
Before starting the engine make certain
that everyone is clear
of
moving parts! Keep away from
sheaves and belts during test procedures.
A
CAUTION:
To avoid damage to the battery
charging circuit, never shut off the engine battery
switch when the engine Is running!
~
WESTERBEICE
Engines & Generators
27