Mitsubishi Eclipse Workshop Manual page 678

54-40
AUDIO SYSTEM
-
Troubteshooting
There
is
noise when starting
the
engine.
Norse type
Sounds are
in
parentheses
(
).
lnspection or
replacement
AM,
FM:
lgnrtion
notse
(Popping,
Snapprng.
Crackrng,
Buzzrng)
.
Increasing the engine
speed
causing
the popping sound to
speed up, and volume
decreases.
.
Disappears when the ignilton
switch is turned
to
ACC.
o
Mainly due to the
spark
plugs.
o
Due
1o
the
engine
notse.
AM.
FM
Defogger
notse
It is generated
when the
defogger j
Wnen the
defoooer
swrtch is turned
on or
off.
I swrtch
rs
turned'än
or
off. spark noise
enters lhe
antenna.
o
Disappears
when the
vehicle
completely stopped
e
Severe
when the clutch
is
engaged.
Occurs when oarts
or
wrnng move
fcr
some
reason and contact
n'retal
parts
of the
bcdy.
Due
to
detachment from
the body of the front
hood, bumpers. exhaust
pipe
and
muffler.
suspension,
etc.
Relurn parts
or
r,vrrinc Ic
their proper position
-
Earth
pans by bonding.
Cases
where the probiem
rs not eliminated by
a
srngre response
to
one
area
are common, due to
severa_l
body parts being
rmperfectly
eartl'ted.
Static eieclricrty
(Cracking Crnklrng)
o Various noises are produced
depending on
the body part of
the
vehicle.
Caution
1.
Connec,ting a high
tension
cable
to the
noise
filter
may destroy the
noise
fiher
and should
never
be
done.
2.
Check
that
there
is
no external noise.
Since
failure due this
may result
in
misdiagnosis
due
to
inability
to
identify the
noise source,
this operation must
be
performed.
3.
Noise prevention should
be performed by
suppressing strong sources
of
noise step by
step.
NOTE
1.
Capacitor
The capacitor does not pass D.C. current, but as
the number of waves increases when it
passes
A.C.
current, impedance (resistance against
@
tvlitsubishi Motors
Corpontion
Apr.
l99l
A.C.) decreases, and current
flow
is facilitated.
A noise suppressing condenser which takes
ad-
vantage of this property is inserted
betrareen
the
power line for the noise source and the
earth.
This suppresses noise by earthing
ihe
noise
in"Iß?l"i!t
(A.c. or pulse sisnat)to1he bodv
of
j
2.
Coil
The coil passes D.C. current, but
impedance
rises
as
the number of waves
increases relative
to
the
A.C. cunent.
A
noise suppressing coil
which takes
advantage
of this
pioperty
ls
in-
serted into the power
line for the noise
source,
and works by preventing
the
noise component
from flowing or radiating out of the
line.
PWUE9010
Or''