Cessna 177 SERIES Service Manual

| 16-39.
TROUBLE
SHOOTING
THE
ALTERNATOR
SYSTEM
(THRU
1977
MODELS)
TROUBLE
PROBABLE
CAUSE
REMEDY
AMMETER
INDICATES
HEAVY
Shorted
radio
noise
filter
1.
Remove
cable
from
output
DISCHARGE
WITH
ENGINE
or
shorted
wire.
terminal
of
alternator.
Check
NOT
RUNNING
OR
ALTERNA-
resistance
from
end
of
cable
TOR
CIRCUIT
BREAKER
OPENS
to ground
(MASTER
SWITCH
WHEN
MASTER
SWITCH
IS
MUST
BE OFF).
If resistance
TURNED
ON.
does
not
indicate
a
direct
short,
proceed
to step
4.
If
resistance
indicates
a
direct
short,
proceed
to
step
2.
2.
Remove
cable
connections
from
radio
noise
filter.
Check
resistance
from the
filter
input
terminal
to ground.
Normal
in-
dication
is
infinite
resistance.
If
reading
indicates
a direct
short,
replace
filter.
If
no
short
is
evident,
proceed
to
step 3.
3. Check
resistance
from
ground
to the
free
ends of
the wires
which
were
connected
to
the radio
noise
filter
(or alternator
is
no noise
filter
is installed).
Normal
indica-
tion
does
not
show
a
direct
short.
If a
short
exists
in
wires,
repair
or
replace
wiring.
Shorted
diodes
in alternator.
4. Check
resistance
from output
terminal
of alternator
to alterna-
tor case.
Reverse
leads
and
check
again.
Resistance
reading
may
show
continuity
in
one direc-
tion
but should
show an
infinite
reading
in the
other
direction.
If an infinite
reading
is not ob-
tained
in at
least
one direction,
repair
or replace
alternator.
ALTERNATOR
SYSTEM
Regulator
faulty
or
improp-
1.
Start
engine
and
adjust
for 1500
WILL
NOT
KEEP
BAT-
erly
adjusted.
RPM.
Ammeter
should
indicate
a
TERY
CHARGED.
heavy
charge
rate
with
all
electri-
cal
equipment
turned
off.
Rate
should
taper
off in 1-3
minutes.
A
voltage
check
at
the
bus
should
in-
dicate
a
reading
consistant
with
the
voltage
ex
temperature
chart
in
the
Cessna
Alternator
Charging
System
Service/Parts
Manual.
If charge
rate
tapers
off very
quickly
and
volt-
age is
normal,
check
battery
for
malfunction.
If ammeter
shows a
low charge
rate
or any
discharge
rate, and
voltage
is
low, proceed
to step 2.
16-10 Change 7

Cessna 177 SERIES Specifications

General

Manufacturer	Cessna
Engine Type	Piston
Wingspan	35 ft 6 in (10.82 m)
Seating Capacity	4
Number Built	4, 295
Engine	Lycoming O-360
Horsepower	180 hp
Maximum Takeoff Weight	2, 500 lb (1, 134 kg)