Installation manual
-·
DC
ELECTRICAL
SYSTEM
7. Now check the voltage between the alternator
ou1put
ter-
minal (B+) and ground.
If
the circuit
is
good, the voltage at
the alternator will be the same as the battery, or
if
an isola-
tor
is
in the circuit the alternator voltage will
be
zero.
If
neither
of
the above is true, a problem exists in the circuit
between the alternator and the battery. Check all the
connections
-look
for
an
opening
in
the charging circuit.
STARTING
BATTERY
TESTING
THE
STARTING
BATTERY/ALTERNATOR
(ENGINE
RUNNING)
·
8. Start the engine again. Check the voltage between the
alternator
0111put
and ground.
The voltage reading
for
a properly operating alternator
should be between 13.5 and 14.5 volts.
If
your alternator
is
over- or under-charging, have it repaired at a reliable
service facility.
NOTE:
Before removing the alternator
for
repair;
use a
voltmeter to ensure that 12 volts
DC
excitation
is
present
at
the EXC tenninal if the previous test showed only bat-
tery voltage
at
the B output terminal.
If
12 volts is not present
at
the
EXC
tenninal, trace the
wiring and look
for
breaks
and
poor connections. '
12
VOLT
DC
CONTROL
CIRCUIT
The engine has a 12 volt
DC
elect:J.ical
control circuit that is
shown on the wiring diagrams that follow. Refer to these
diagrams when troubleshooting or when servicing the
DC
elect:J.·ical
system.
A
CAUTION:
To
avoid
damage
to
the
battery
charging
circuit,
never
shut
off
the
engine
battery
switch
while
the
engine
is
running.
Shut
off
the
engine
battery
switch,
however,
to
avoid
electrical
shorts
when
working
on
the
engine's
electrical
circuit.
·
BATTERY
The recommended "dedicated" battery used for the engine's
starting 12 volt DC control circuit should be 800-1000 Cold
Cranking Amps (CCA) rated.
36
Checking
the
Service
Battery
Check the voltage
of
the service battery. This battery should
have a voltage between
13
and 14 volts when the engine
is
running.
If
not, there is a problem in the service battery
charging circuit. Troubleshoot the service battery charging
circuit by checking the wiring and connections, the solenoid,
isolator, battery switch, and the battery itself.
MULTIMETER
00J
0
COM
GROUND
.
SERVICE
BATTERY
TESTING
THE
SERVICE
BATTERY
(ENGINE
RUNNING)
A
CAUTION:
To
avoid
damaging
the
alternator
diodes,
do
not
use
a
high
voltage
tester
(i.e.
a
megger)
when
pertonning
tests
on
the
alternator
charging
circuit.
Battery
Care
Review the manufacturer's recommendations and then
establish a systematic maintenance schedule for your engine's
starting batteries and house batteries.
D Monitor your voltmeter for proper charging during engine
operation.
D Check the
elect:J.·olyte
level and specific gravity with a
hydrometer.
D Use only distilled water to bring
elect:J.·olytes
to a proper
level.
D Make certain that battery cable connections are clean and
tight to the battery posts (and to your engine).
D Keep your batteries clean and free
of
corrosion.
A
WARNING:
Sulfuric
acid
in
lead
batteries
can
cause
severe
burns
on
skin
and
damage
clothing.
Wear
protective
gear.