Voltage Regulator; Rectifier - Honda CB350 Repair Manual

114 ELECTRICAL SYSTEM
2. If the battery discharges quickly, or
fails to hold a charge, check the battery,
the regulator, rectifier, and alternator.
3. Checks for battery condition are
outlined in Chapter 2, "Maintenance."
For other components, consult the fol—
lowing.
VOLTAGE REGULATOR
A bad voltage regulator may cause the
battery to go dead, or may overcharge it
causing electrolyte loss, short light bulb
life, etc. The regulator is located beneath
the battery box, and is rubber mounted. It
can be tested with an ohmmeter, continu—
ity tester, or ammeter.
Voltage regulator location
1. If the battery goes dead, disconnect
the three regulator leads (yellow, green,
and black).
2. With an ohmmeter or continuity
light, check for continuity between the
yellow lead and the green lead. Check for
continuity between the yellow lead and
the motorcycle frame.
There must not be continuity in ei—
ther case. If there is, the regulator must
be replaced.
3. If an ammeter is available, connect
it in series with the battery positive wire.
Start and run the engine at more than
2,000 rpm. If the ammeter indicates that
the battery is discharging, disconnect the
regulator yellow lead and repeat the test.
If the battery now shows that it is receiv—
ing a charge, the regulator must be re—
placed. If no change is noted, proceed
with the rectifier and alternator tests
which follow.
4. If the battery overcharges, check as
follows:
Assuming that the battery is in good
condition and fully charged, start the
engine and connect a good voltmeter
across the battery terminals. Run the
engine at 4,000 rpm. The voltage across
the battery should increase to between
14—15 volts, but not more. If the meter
reads more than 15 volts, the regulator
must be replaced.
NOTE: This test will not be valid
unless the battery is fully charged. To
check this, run the engine until the
voltage stabilizes, then disconnect the
regulator black lead. If the voltage in—
creases, the results of the test were
valid.
5. When mounting the regulator, be
sure that the rubber dampers are in place.
The regulator could be damaged by
excess vibration.
RECTIFIER
The rectifier is located behind the bat—
tery (350) or under the battery case.
The rectifier should be checked in the
event of insufficient battery charging.
Tests can be carried out with a continuity
light or a standard (low—voltage) ohmme—
ter.
CAUTION: Do not apply high—voltage
to the rectifier.
1. Disconnect the leads and remove
the rectifier from the machine.
2. The test involves testing current
flow through the rectifier in both direc—
tions. As noted in the "Operational De—
scription," the rectifier consists of four
diodes. When in working condition, a
diode will pass current in one direction
only.
If the diode passes current in both di—
rections, or in neither direction, it is de—
fective. If any of.the diodes is defective,
the rectifier must be replaced.
(4) (3) (2) (1)
Rectifier wires: (1) green, (2) red/white, (3) yellow,
(4) pink