Mooney M20K - Page 91

SERVICE
AND
MAINTENANCE
MANUAL
M20K
MOONEY
AIRCRAFT
CORPORATION
CAUTION
Pull
alternator
field GIB.
Start
engine;
while
at
idle
RPM
reset
GIB.
Slowly
increase
RPM
while
monitoring
bus
voltage.
DO
NOT
EXCEED
14
vo~ts,(25-0001125-0999);28
volts
for
(25-1000
thru
25-TEA).
Defective
wiring
regulatorto
4.
Check
resistance
from
F2
a8emator.
terminar
of
attemator
to
pin
B
or
2
cc of
reg.
plug.
Normal
indication
is
a
very
low
resistance.
If
reading
indicates
no,
or
poor
continuity,
repair
or
replace
wiring
from
regulator
to
altemator.
+25-0001
thru
25-0999;
field
terminal
for
25-1000
thru
25-1230.
cc25-0001
thru
25-0999;
Pin
7
on
25-1000
thru
25´•1230.
Defective
alternator.
5.
Check
resistance
from
F2
to
F1
term.
of attemator.
Normal
indication
is
3
4
ohms.
If
resistance
is
high
or
low,
repair
or
replace
alternator.
25-0001
thru
25-0999;
case
to
field,
25-1000
thru
25-TEA.
6.
Check
resistance
from
F2
terminal
of
attemators
to
altemator
case.
Normal
indication
is
high.
If
resistance
is
low,repair
or
replace
a~1250001--25-0999)
243992
GENERATOR
TROUBLE
SHOOTING.
(For
Standby
Generator)
(25-0001
thru
25-0999)
TROUBLE
PROBABLE
CAUSE
REMEDY
Generator
operating
within
Generator
operating
on
residual.
Check
for
loose
or
high
resistance
t~ated
speed range,
but
voltage
connections;
clean
and
tighten
outputlow.
terminals.
Loose
or
high-resistance
electrical
Clean
and
tighten
all
electrical
connections.
connections.
Excessively
wom
brushes.
When
brush
wears
down
to
.700
inch,
replace
with
a
new
one.Do
not
use
abrasives
of
any
descn’ption
to
seat
brushes.
Brushes
binding
in
brush
box
Brushes
should
fd
free
without
excessive
side
play
in
brush
boxes.
Clean
binding
brushes
and
brush
boxes
with a
cloth
moistened
in
Varsol or
unleaded
gasoline.
Excessive
brush
side
play
in
Replace
brushes.
brush
box
Brushes
not
properly
seated.
Reseat
brushes.
Low
brush
spn’ng
tension.
Brush
spn’ng
should
bear
centrally
on
top
of
brushes,
insuring
full
brush
contact
with
face
of
commutators.
Dirty
commutator.
Clean
commutator
with
a
cloth
moistened
in
Varsol or
unleaded
gasoline.
Scored
or
pitted
commutator.
Tum
down
or
replace
commutator.
24-39-02
13
OLDWILLWAYNE