Piper Navajo PA-31 Service Manual page 700

PIPER NAVAJO SERVICE MANUAL
11-6.
ALTERNATOR AND COMPONENT. (DELCO-REMY 50 ampere.)
11-7. CHECKING ALTERNATOR SYSTEM.
The ammeter
is equipped with two
selector switches
which enable an independent
output check of each alternator,
as well as the electrical
output-input
of the battery.
Should either
alternator
show no output on the ammeter,
check the appropriate
circuit breakers.
If a
further check of the ammeter
shows no output from both alternators,
switch to
the auxiliary
voltage
regulator and overvoltage
relay.
If switching to the aux-
iliary system indicates
no electrical output, further
check the alternator
system.
(Refer to Figure
11-3.)
a.
Ascertain that the ammeter
is operating properly.
b. Disconnect the battery
(BAT) and field (F) leads at the alternator.
c. Ascertain
that all electrical
units are off and the battery is fully charged.
d. Turn on the master
switch.
e. To check the alternator
output circuit, connect a voltmeter
or 28-volt test
light to the battery lead and to ground.
If a reading
of approximately
28-volts
registers
on the voltmeter
or the test light lights,
the battery
circuit is oper-
ational.
f. Should there be no indication of voltage, trace back through the output cir-
cuit until voltage is indicated.
(Refer to Figure 11-3.)
A component that allows
no voltage
to pass through it should be replaced.
g. To check the field circuit,
connect
a voltmeter to the field lead and to
ground.
If voltmeter indicates
any voltage, the field circuit
is operational.
Both
the main and auxiliary
field systems
may be checked in a like manner.
h. If voltage is indicated at both the batterylead
and field lead, the alternator
should then be checked
for possible
malfunction.
(Refer to Paragraph
11-9.)
11-8. ADJUSTMENTS.
The onlyadjustmentnecessaryto
maintain thealternator
system
is the adjustment
of the voltage control on the voltage regulator.
A volt-
age of 28-volts
is maintained.
All other control adjustments
are made at time
of installation
and need not be reset.
Reissued: 10/12/79
ELECTRICAL SYSTEM
Effectivity
4A22
DELCO