TABLE
2.
TESTING SYNCHRO
20 AMP
SYSTEM
TEST
Battery voltage
-
unit
not running
Battery voltage with
unit running
at 1800
rpm
or
more
AC voltage from stator
with plug disconnected
and unit running
at
approximately
1800 rpm
VALUE
12 Volts
DC
14.2
— 14.8*
Volt
DC
17 volts
AC
Black
to
Black
Ohmmeter reading
at
plug
when checking
two AC
stator leads
-
unit
not
running
Resistance values (Ohms)
are as
follows
between wire pairs.
.5-.7
•BLACK
1.8-2.2x1
•BLACK
1.3-
LSA
•RED
*
- 60
Volt minimum
at
greater than 2000
rpm,
Red
to
Ground.
Checking Rectifier Assembly: Examine each
of the
two diodes
for
breakdown
by
connecting ohmmeter
(Rxl scale) from
one
black lead
to
white
lead.
Meter
should read
10
ohms
in
proper polarity.
A
shorted
diode would read zero resistance
and
would cause
a
short circuit through
the
lead winding when
in
operation.
An
open diode would read infinite
in
both
directions indicating that replacement
is
necessary.
Testing Regulator Assembly:
To
check
for
proper
voltage regulation, attach
a DC
voltmeter
to
battery
and operate engine
at
about
1800 rpm.
Battery
voltage will climb
to the
preset factory setting (14.2
to
14.8 volts).
Some installations
may
vary
due to
voltage drop
in the
length
of
ammeter harnesses. Other variations
may
stem from
a
loose
connector
in the
harness
or
loose
or
corroded battery leads.
Low
voltage readings
at the
battery mean poor battery connections.
To test regulator, remove connector. Using
the
RxlO.OOO scale
of
your ohmmeter, connect one meter
lead
to red
leadwire and other meter lead
to
regulator
base.
No
deflection should be noted on the ohmmeter
in either polarity. Next connect meter
to
black
leadwire
and
base
of
regulator. Meterwill deflect fully
in
one
polarity with
no
deflection
in the
other.
ALTERNATOR STATOR
MOUNTED BEHIND BLOWER WHEEL
TO TERMINAL
CONNECTOR
RECTIFIER
ASSEMBLY
REGULATOR
ASSEMBLY
FIGURE
29. 20 AMP
SYNCHRO SYSTEM
Full Charge—Will
Not
Regulate: Check
for
broken
leads
at
connection
to
regulator plates.
To be
sure
regulator winding operates properly, connect
red
lead
to
ground
and
start engine.
A
maximum
of 4
amperes should
be
noted. This would indicate stator
winding
is
satisfactory.
If so,
replace regulator.
No Charge:
If
alternator does
not
charge when load
is
applied
to
battery, shut
off
engine and disconnect one
red leadwire from regulator terminal.
Be
sure lead
is
taped
or
isolated from conducting engine parts. Once
again,
start engine. Alternator should charge
to
full
output;
if it
doesn't, replace stator assembly.
15
AMP
PHELON
SYSTEM
The
15 amp
flywheel alternator systems (Figure
30)
have
a one
piece regulator-rectifier assembly.
Various alternator problems
are
listed
in
Table
3.
Testing
With
the
engine running between 1800-2600
rpm,
observe
the
panel ammeter
(if not
already equipped,
connect
a
test ammeter).
If no
charging
is
evident,
proceed with
the NO
CHARGE TEST.
If
ammeter
shows
a
constant higher charge rate, follow the HIGH
CHARGE RATE TEST procedure.
No Charge Test: Perform
as
follows:
1.
Check
the B+ to
ground voltage using
a DC
voltmeter.
See
Figure 31
for
wiring diagram.
2.
If
voltmeter reads 13.8 volts
or
higher, add
a
load
to system
(e.g.
headlights)
to
reduce battery
voltage
to
below
13.6
volts.
3. Observe ammeter.
If
charge rate increases,
con-
sider
the
system
as
satisfactory.
If
charge rate
does
not
increase, proceed with testing.
4.
Disconnect plug from regulator-rectifier and test
the
AC
voltage
at the
plug with engine running
near 3600
rpm. If AC
voltage reads less than
28
volts,
replace the stator.
If
AC voltage is more than
28 volts, replace the regulator-rectifier assembly.
28
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