Mooney M20K - Trouble Shooting Charts

SERVICE
AND
MAINTENANCE
MANUAL
M20K
MOONEY
AIRCRAFT CORPORATION
26~38-00
-MISCEUANEOUS
CIRCUITS
CURRENTSENSOR
-ADJUSTMENT
Effective
SIN 25-2000
thru
25-TEA
i. Tum
Coordinator
Circuit.
The
tum
coordinator
is
a
flight
instrument
which
A. Remove
front
cover
from
Annunciator.
operates
from
an
electrical
power
source.
B.
Start
engine
and
Nn
at
moderate
speed
until
2.
Heated
Pitot
Tube.
ammeter
charge
rate
drops
to
near zero.
A
circuit
breaker
switch controls
the
pitot
tube
heater.
C.
Tum
all
equipment
OFF
avionics,
lights, pitot
3.
Hour
Meter
(Optional).
heat,
etc.,
so
only
the
equipment
connected
to
buss
is
The
hour
meter
operates
directly
from the altemator
operating
(instruments
only).
"Aux"
terminal
through
a
fused
wire
on
SM
25-0001
thru
25-0445.
SM 25-0447 and
later models hour
D.
Tum
Right
Altemator
field
switch
OFF.
meter
operates
from
the
electn’c tachometer. A
Hobbs
E.
Adjust
LH
potentiometer
clockwise
until
light
meter
may
be
installed
as an
option.
illuminates;
then
counterclockwise
until
light
is
4.
Cigar
Lighter.
e>dinguished.
A
cigarlighter
is
mounted in
the
n’ght
instrument
panel.
F.
Tum
Left
AReemator
OFF
and
turn
Right
5.
Current
Sensor
(Monitor).
Alternator
ON.
(Reference
Figure 24-3)
G.
Repeat
Steps
E
3
F
with RH
potentionmeter.
H. Turn
both
attemators
ON;
if
either
light
illominates,
adjust
apppropn’ate
potentionmeter
slightly
counterc(ockwise
until
light
is
e>dinguished.
I.
Replace
cover
and
secure
in
original
location.
INSTRUMENT
LIGHT
BULBS
(TYPICAL)
ALTERNATOR
NULL
ADJUST.
SCREWS
O
NORM CAL
(3
000
0000
O O
b
000
O
o
O
O
b
LEFT FUEL
(LH)CHIO-ALT
AD3-CHI i
(RH)
Fuel
Warn.
Adi.
Screws
FIGURE
24-3 CURRENT MONITOR
ADJUSTMENT
24-39-00
-TROUBLE
SHOOTING CHARTS
2439-01
-ALTERNATOR
TROUBLE SHOOTING
TROUBLE
PROBABLE CAUSE
REMEDY
Alternator
over-charges battery;
Regulator
faulty.
Check
bus
voltage
with
engine
battery
uses
excessive
water.
running.
Observe
aircraft
ammeter.
Ammeter
should
indicate
near
zero
after ten
minutes
of
engine
operation.
Replace
voltage
regulator
if
defective.
ALT
FIELD
circuit breaker
trips.
Circuit shorted
in
wiring.
Disconnect
lead from
pin
A
or
1
of
regulator,
and
reset
circuit
(25-0001
thru
25-0999;
Pin
5 for 25-1000
thru
25-1230)
breaker.
If
circuit
breaker
trips,
check
win’ng.
24-38-00
OLDWILLWAYNE