Installation manual
DC
ELECTRICAL
SYSTEM
7. Now check the voltage between the alternator output 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.
TESTING
THE
STARTING
BATTERY/ALTERNATOR
(ENGINE
RUNNING)
M
ULTIMETER
WITCH
~ta+
I
(]Z5J
G
COM
!_-
'iL
ENG
IN
E
GROUND
8. Start the engine again. Check the voltage
between
the
alternator output 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
terminal if
the
previous test showed only
bat-
tery
voltage
at
the
B output
terminal.
If
12
volts
is
not present at
the
EXC terminal, trace
the
wiring
and
look
for
breaks
and poor connections.
12
VOLT
DC
CONTROL
CIRCUIT
The engine has a 12 volt
DC
electrical control circuit that
is
shown on the wiring diagrams that follow.
Refer
to these
diagrams when troubleshooting
or
when servicing
the
DC
electrical 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.
BAnERY
The minimum recommended capacity
of
the battery used
in
the engine's 12 volt
DC
control circuit is
600-900
Cold
Cranking Amps (CCA).
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.
23
MULTIMETER
i
COM
GROUND
,SERVICE
BATTERY
TESTING
THE
SERVICE
BATTERY
(ENGINE
RUNNING)
A
CAUTI,ON:
To
avoid
damaging
the
alternator
diodes,
do
not
use
a
high
voltage
tester
(I.e.
a
megger}
when
performing
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
electrolyte level and specific gravity with a
hydrometer.
D Use only distilled water to bring electrolytes 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
causa
severe
burns
on
skin
and
damage
clothing.
Wear
protective
gear.