Piper Cherokee Six - Page 599

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
10-71.
DESCRIPTION.
The
annunciator
panel
is
a small
cluster
of
lights
which
warn
of
malfunctions
in
the
various
circuits
or
systems.
A
malfunction
is
identified
by
the
illumination
of
an
individual
warning
light.
There
are
three
amber
warning
lights
and
a
push-button
test
switch.
(Refer
to
Figure
9-4d.)
Power
is
supplied
from
the
bus
bar
through
a
5
amp
fuse
located
behind
the
suction
gauge.
The
VAC
warning
light
is
controlled
by
a vacuum
sensor
switch
located
at
the
bulkhead
and
is
attached
to
the
vacuum
regulator.
The
sensor
switch
will
activate
when
the
differential
pressure
is
below
3.5
in.
Hg.
The
OIL
warning
light
is
controlled
by
an
oil
pressure
sensor
switch
incorporated
in
the
oil
line
to
the
oil
pressure
gauge
and
is
located
at
the
bulkhead.
The
sensor
switch
will
activate
when
the
oil
pressure
is
below
35
psi.
The
ALT
warning
light
is
illuminated
by
current
flowing
from
the
bus
bar
to
the
alternator
circuit.
(Refer
to
Figure
10-52.)
This
condition
exists
when
the
alternator
is
not
operating
properly
and
the
output
is
zero.
During
normal
operation,
the
alternator
warning
circuit
is
also
supplied
with
power
from
the
top
diode
terminal.
This
current
flows
through
a
5
amp
fuse,
located
above
the
diode
heat
sink,
to
the
resistor
and
diode
creating
a
no-flow
condition
which
does
not
allow
the
warning
light
to
light.
The
test
button
is
used
to
check
the
operation
of
the
lights
when
the
engine
is
running.
The
lights
will
work
when
the
engine
is
not
running
with
the
master
switch
turned
on.
10-71A.
REMOVAL
OF
ANNUNCIATOR
PANEL
(Refer
to
Paragraph
9-74)
10-72.
REMOVAL
OF
OIL
PRESSURE
SENSOR.
Access
to
the
sensor
unit
is
gained
by
reaching
up
under
the
instrument
panel.
Removal
is
accomplished
by
the
following:
a.
Disconnect
the
two
electrical
leads.
b.
Unscrew
the
sensor
unit
from
the
bulkhead
fitting.
c.
Catch
spillage
and
cover
hole
to
prevent
foreign
matter
from
entering
oil
line.
10-73.
INSTALLATION
OF
OIL
PRESSURE
SENSOR.
a.
Screw
the
sensor
unit
into
the
bulkhead
fitting.
b.
Reconnect
the
two
electrical
leads.
c.
Perform
operational
check.
1 0-74.
REMOVAL
OF
VACUUM
SENSOR.
Access
to
the
sensor
unit
is
gained
by
reaching
up
under
the
instrument
panel
to
the
vacuum
regulator.
Removal
is
accomplished
by
the
following:
a.
Disconnect
the
two
electrical
leads.
b.
Unscrew
the
sensor
unit
from
the
vacuum
regulator.
c.
Cover
hole
to
prevent
foreign
matter
from
entering
regulator.
10-75.
INSTALLATION
OF
VACUUM
SENSOR.
a.
Screw
sensor
unit
into
vacuum
regulator.
b.
Reconnect
the
two
electrical
leads.
c.
Perform
operational
check.
ELECTRICAL
SYSTEM
Revised:
12/15/80
3C23