Mitsubishi Galant (2004+). Manual — part 1486

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CHASSIS ELECTRICAL

54A-187

STEP 18. Check rear speaker (RH) connector D-09 and
audio amplifier connector C-113 for loose, corroded or
damaged terminals, or terminals pushed back in the
connector.
Q: Are harness connectors D-09 and C-113 in good

condition?
YES : Go to Step 19.
NO : Repair or replace the component(s). Refer to GROUP

00E, Harness Connector Inspection

P.00E-2

. The

rear speaker (RH) should sound.

AC305233CC

CONNECTOR: C-113

HARNESS SIDE

AC305268

AS

CONNECTOR: D-09

HARNESS SIDE

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CHASSIS ELECTRICAL

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STEP 19. Check the wiring harness between rear speaker
(RH) connector D-09 (terminals 1 and 2) and audio
amplifier connector C-113 (terminals 9 and 1).

NOTE: Also check intermediate connector C-13 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-13 is damaged, repair or
replace the connectors as described in GROUP 00E, Harness
Connector Inspection

P.00E-2

.

Q: Is the wiring harness between rear speaker (RH)

connector D-09 (terminals 1 and 2) and audio amplifier
connector C-113 (terminals 9 and 1) in good condition?
YES : Replace the audio amplifier. The rear speaker (RH)

should sound.

NO : Repair the wiring harness. The rear speaker (RH)

should sound.

AC305234

CONNECTORS: C-13, C-113

C-13

HARNESS SIDE

C-113

C-113

C-13

BB

AC305268

AS

CONNECTOR: D-09

HARNESS SIDE

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CHASSIS ELECTRICAL

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INSPECTION PROCEDURE 8: Noise is Present while Moving (AM).

STEP 1. Ask the driver about the noise.
(1) Find out the following information from the owner.
(2) Place where the noise occurs.
(3) Locality conditions (valley, mountain, etc).
(4) Name and frequency of stations affected by

noise.

Q: What type of noise is detected, vehicle noise or

external noise?
Vehicle noise :

It may not be possible to prevent

noise if the signal is weak. Go to step 2.

External noise :

In almost all cases, prevention on

the receiver side is next to impossible when
the signal is weak. Go to Step 4.

STEP 2. Ask the driver about the location where
the noise occurs.

Q: Does the noise occur when entering or near a

particular structure (building, tunnel, mountain,
etc)?
YES :

Go to Step 3.

NO :

Go to Step 4.

STEP 3. Check if the noise can be eliminated by
adjusting the radio.
(1) Adjust the radio as follows.
(2) Change to a different station with a stronger

signal. This will boost the systems resistance to
outside interference.

(3) Suppress high tones to reduce noise.

Q: Has the noise been eliminated?

YES :

The noise has now been eliminated. Inform

the customer that it is normal to hear noise
while receiving a weak station.

NO :

Go to Step 4.

STEP 4. Check for the noise.

Q: Does noise still exist?

YES :

If there is still more noise than on other

similar radio’s find out the type of noise. Ask
the owner for the name and frequency of the
affected stations, and consult with the radio
manufacturer service center.

NO :

System is operating normally.

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INSPECTION PROCEDURE 9: Noise is Present while Moving (FM).

.

DIAGNOSIS
NOTE: FM waves have the same properties as light,
and can be deflected and blocked. FM signal recep-
tion is severely degraded in the shadow of obstruc-
tions such as buildings or mountains. An FM receiver
will then only receive a reflected signal.
1. The signal becomes weak as the distance from

the station's transmission antenna increases. The
signal strength received depends on the signal
strength of the transmitting station and intervening
obstructions such as buildings and hills. Generally
speaking, the area of good reception is
approximately 20

− 25 km (12 − 16 miles) for

stereo reception, and 30

− 40 km (19 − 25 miles)

for monaural reception.

2. The signal will becomes weak when an area of

shadow from the transmitting antenna (places
where there are obstructions such as mountains
or buildings between the station transmitter and
the vehicle), and noise will appear. <This is called
first fading, and gives a steady buzzing noise.>

3. If a direct signal hits the antenna at the same time

as a signal reflected by obstructions such as
mountains or buildings, interference of the two
signals will generate noise. When moving, noise
will appear each time the vehicle's antenna
passes through this kind of obstructed area. The
strength and interval of the noise varies according
to the signal strength and the conditions of
deflection. <This is called multipath noise, and is a
repetitive buzzing.>

4. Since FM stereo transmission and reception has a

weaker field than monaural, it is often
accompanied by a hissing noise.

After taking measures to prevent the noise, check
that no noise occurs.
5. Change to a different station with a stronger wave

to boost resistance to interference.

6. Suppress high tones to reduce noise.
7. Does vehicle have an antenna which extend? If

not eliminate this step.

If there is noise, the following causes can be consid-
ered.
8. If due to vehicle noise: It may not be possible to

prevent noise if the signal is weak.

9. If due to external noise: In almost all cases,

prevention on the receiver side is not possible.
Weak signals especially are susceptible to
interference.

If there is more noise than on radios in other vehi-
cles, find out the noise condition and the name and
frequency of the receiving stations from the owner,
and consult with the radio manufacturer's service
center.

ACX01869

10kW
OUTPUT FM
BROAD CAST

FOR STEREO:
20 - 25 km
(12 - 16 miles)

FOR MONAURAL:
30 - 40 km (19 - 25 miles)

FOR HOME STEREO:
80 - 90 km (50 - 56 miles)

MALTIPATH INTERFERENCE

FIRST FADING
INTERFERENCE

AC