Radio And Tape Player; Troubleshooting - Mitsubishi Lancer Evolution-IV Workshop Manual

CHASSIS ELECTRICAL –

RADIO AND TAPE PLAYER

TROUBLESHOOTING

There is noise when the engine is running.
Kind of Noise (Parenthe-
sized is how noise
sounds.)
AM, FM: Ignition noise
(Popping, snapping,
crackling, buzzing)
AM, FM: Defogger noise
(1) (Murmuring)
AM, FM: Defogger noise
(2) (Snapping noise)
AM, FM: Defogger noise
(3) (Scratching, gaggling)
AM, FM: Wiper motor
noise (Humming, wheez-
ing)
FM: Mirror motor noise
(Humming, wheezing)
Other electrical compo-
nents
Static electricity (Crack-
ling, crinkling)
Caution
(1) Never let the noise filter contact a high tension cable. The noise filter could break down.
(2) Check that there is no external noise. This check is necessary to prevent misidentification of noise
sources.
(3) Noise prevention should be performed by eliminating noise sources in the descending order of loudness.
Symptom
D
Popping sound becomes
faster with the increase
of engine speed.
D
The noise is lost with
ignition switch turned to
ACC.
Occurs when the defogger
switch is turned to ON and
OFF.
Occurs when the defogger
switch is turned to ON.
Occurs when the defogger
switch is turned to ON with
print heater wire broken.
Sound becomes faster with
the increase of wiper speed
and is lost when the wiper is
stopped.
Occurs when electric mirror
operates.
–
D
Noise is stopped when
the vehicle comes to a
complete stop.
D
Noise becomes louder
when the clutch
released.
Various noises are produced
by body parts.
Radio and Tape Player
Cause
D
Mainly due to the
spark plugs.
D
Due to noise circula-
tion from elsewhere
D
Noise from the engine
Noise produced by spark-
ing when the defogger
switch is turned to ON/
OFF enters the glass
antenna.
Noise produced by current
flowing in the defogger
enters the glass antenna.
Noise produced by spark-
ing where print heater is
broken enters the glass
antenna.
Caused by sparking in
wiper motor brush.
Caused by sparking in
mirror motor brush.
Noise is emitted by some
electrical components in
long use.
Occurs when parts or
wiring move for some
reason and contact metal
parts of the body.
is
Due to electrical detach-
ment of the hood, exhaust
pipe and muffler, suspen-
sion, etc. from the body.
54-45
Remedy
Check the noise capacitor
and earth cable and
replace if necessary. (See
Fig. 1 and Fig. 2.)
Check the noise capacitor
and replace if necessary.
(See Fig. 1.)
Check the choke coil and
replace if necessary.
(See Fig. 3.)
Repair the print heater.
Replace the wiper motor.
Replace the electric
motor.
Repair or replace electri-
cal components.
Put parts or wiring into
position.
Tighten mounting bolts
securely. In many cases,
remedy of one part does
not eliminate the problem
due to incomplete earthing
elsewhere.