Westerbeke 5.0Kw BCDR Operator's Manual page 34

ALTERNATORS TESTING/TROUBLESHOOTING
TESTING THE
OUTPUT CIRCUIT
ENGINE RUNNING
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TESTING THE EXCITATION CIRCUIT
1. Connect the positive (+) multimeter probe to the
excitation terminal R on the alternator and the negative
(-) lead to the ground terminal E on the alternator.
2.
Tum
the ignition switch to the on position and note
the multimeter reading. The reading should be 1.3 to
2.5 volts (see illustration).
3. If the reading is between .75 and
1.1
volts, the
rotor field circuit probably is shorted or grounded.
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 exc terminal R.
Connect the positive multimeter probe to the excitation
lead and the negative inultimeter probe to ground
terminal
E.
If the multimeter now indicates an
approximate battery voltage, the voltage regulator is
defective and must be replaced. If no voltage is
indicated, check the excitation circuit for loose or dirty
connections or damaged wiring. ___ -.-_
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.
NOTE:
WESTERBEKE'S service Manual has detailed
instructions for the disassembly and repair of their
standard alternators.
BATIERYCARE
The minimum recommended capacity of the battery used in
the engine's 12 volt DC control circuit is 600 - 900 Cold
Cranking Amps (CCA).
Review the manufacturer's recommendations and then
establish a systematic maintenance schedule for your
engine's starting batteries and house batteries.
• Monitor your voltmeter for proper charging during
engine operation.
• Check the electrolyte level and specific gravity with a
hydrometer.
• Use only·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).
SPECIFICATIONS
The minimum recommended capacity of the battery used in
the engine's l2-volt DC control circuit is 600-900 (CCA).
Engines & Generators
29A