Mooney M20M - Page 144

SERVICE
AND
MAINTENANCE
MANUAL
M20M
MOONEY
AIRCRAFT
CORPORATION
TROUBLE
(con’t.)
PROBABLE CAUSE
REMEDY
Bus
Load/Ammeter
flickers
Loose
or
poor
connection;
timer
If trouble
occurs
only
part
of
cycle,
between
90
second
phase
to
De-leers.
determine
which De-leer
is
affected,
periods.
(con"t.)
check
for
rough
or
dirty
slip rings
causing
brush
to
skip.
Check
circuits
for
loose
or
poor
connections.
Timer
cycles
erratically.
Test
timer
per
Section
30-63-00.
Radio noise
or
interference
with
Brushes
arcing.
Check
brush
alignment.
Check
for
dirty
De-leers
on.
or
rough
slip
rings.
If
found, clean,
machine
or
replace
slip ring
assembly.
Check
slip ring alignment.
Loose connection.
See
"Buss load
meter/ammeter
flicks
between
90
second
periods"
above.
Switch
or
circuit breaker
faulty.
Place
jumper
wire
across
switch
or
circuit
breaker;
if radio
noise
disappears,
replace
switch
or
circuit
breaker.
Wiring
too
close
to
radio
Relocate
De-leer
wiring
at
least
8"
from
equipment
or
associated
wiring.
radio
equipment
and
wiring.
Cycling
sequence
not
correct.
Crossed
connections
between
Check
system
wiring
against
circuit
timer
and De-leers.
diagram.
Rapid
brush
wear
or
frequent
Brush block
out
of
alignment.
Check brush
alignment.
Correct
as
breakage.
required.See
section
3.3.3
of
McCauley
Manual
No.
830415.
Slip
ring
wobbles.
Check
slip ring alignment
with
dial
indicator
per
Section
30-69-00.
Rough slip
rings.
Re-machinelre-finish.
Dirty
slip
ring
surfaces.
Clean
slip
rings
with
MEK.
Brushes
arcing.
Check brush
alignment.
30-62-00
-FIOT
USED
30-63-00
DE-ICER
TIMER
CHECK
Experience
in
the
field has
indicated
that
often
the timer is
considered
defective
when the
source
of the
trouble lies
elsewhere.
For this
reason,
the
tests
should be
performed
before
the
timer
is
removed
as
defective.
Refer
to
manufacturer’s
service
data,
McCauley
Manual No.
830415,
Section
4,
for
test
criteria.
TIMING
SEQUENCE
TIME ON
AREAS
OF PROP
DE-ICERS
HEATED
Terminal
C
90
sec.
All
Blades
ON
then
OFF
30-64-00
100
HOUR
INSPECTIONS
30-65-00
CONTINUITY
TEST
After
removing
plug
from
timer,
use
ohmmeter
to
check
Refer
to
manufacturer’s
service
inspection
data
for
continuity
from:
these
steps.
(McCauley
Manual
No.
830415,
Section
4)
1.
Terminal
C
to
outboard
terminal
of
one
prop
boot.
2.
Terminal
G
to
airframe
ground.
CAUTION
3.
Ground
terminal
of
one
prop
boot
to
ground.
Stand
clear of
propeller,
verify
magnetos
are
OFF.
Use
extreme
caution
during
this
procedure.
4-99
30-62-00
19
OLDWILLWAYNE