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Mitsubishi Pajero Pinin. Manual - part 334

CHASSIS ELECTRICAL –

Radio and Tape Player

Earth
cable

Fig. 1

54A-52

A-4 There is noise when starting the engine.

Noise type
Sounds are in
parentheses ( ).

Conditions

Cause

Remedy

FM/MW/LW:
Ignition noise
(Popping, snap-
ping, cracking,
buzzing)

Increasing the engine speed
causing the popping sound to
speed up, and volume
decreases.

Disappears when the ignition
switch is turned to ACC.

Mainly due to the spark
plugs.

Due to the engine noise.

Check or replace the
earth cable. (Refer to
Fig. 1 on P.54A-59.)

Check or replace the
noise capacitor.

Other electrical
components

–

Noise may appear as electri-
cal components become old-
er.

Repair or replace electrical
components.

Static electricity
(Cracking, crin-
kling)

Disappears when the vehicle
is completely stopped.

Severe when the clutch is
engaged.

Occurs when parts or wiring
move for some reason and
contact metal parts of the
body.

Return parts or wiring to their
proper position.

Various noises are produced
depending on the body part of
the vehicle.

Due to detachment from the
body of the front hood,
bumpers, exhaust pipe and
muffler, suspension, etc.

Tighten the mounting bolts
securely. Cases where the
problem is not eliminated by
a single response to one
area are common, due to
several body parts being
imperfectly earthed.

Caution
1.

Connecting a high tension cable to the noise
filter may destroy the noise filter and should
never be done.

Check that there is no external noise. Since
failure caused by this may result in
misdiagnosis due to inability to identify the
noise source, this operation must be
performed.

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 A.C.) decreases, and current flow is
facilitated. A noise suppressing condenser
which takes advantage of this property is
inserted between the power line for the noise
source and the earth. This suppresses noise
by earthing the noise component (A.C. or pulse
signal) to the body of the vehicle.

Coil
The coil passes D.C. current, but impedance
rises as the number of waves increases relative
to the A.C. current. A noise suppressing coil
which takes advantage of this property is
inserted into the power line for the noise source,
and works by preventing the noise component
from flowing or radiating out of the line.

CHASSIS ELECTRICAL –

Radio and Tape Player

54A-53

A-5 Some noise appears when there is vibration or shocks during travelling.

Are connectors properly connected?

Ensure proper connection.

Yes

Does noise appear when the radio switch is turned on while the
vehicle is stopped and the radio is struck while tuned away from
a station?

Static electricity noise:
Body static electric from the shock absorber rubber bushings used
to prevent vibration, tyres, etc. occurs because of separation from
the earth, causing a buzzing noise. Since no measures can be
taken on the radio side, other steps should be taken to discharge
the static electricity of the vehicle body.

Yes

Is the radio correctly earthed? (Is the mounting screw tightened
securely?)

Tighten the screw securely.

Yes

Is the antenna correctly earthed? (If noise appears when the anten-
na is moved, this means the earth is not securely connected.)

If rust is present at the antenna earth screw, clean and tighten
the earth securely.

Yes

Repair or replace radio.

A-6 Ever-present noise.

Noise is often created by the following factors, and
often the radio is OK when it is checked individually.

Travelling conditions of the vehicle

Terrain of area travelled through

Surrounding buildings

Signal conditions

Time period

For this reason, if there are still problems with noise
even after the measures described in steps A-1
to A-8 have been taken, get information on the
factors listed above as well as determining whether
the problem occurs with FM/MW/LW, the station
names, frequencies, etc., and contact a service
centre.

CHASSIS ELECTRICAL –

Radio and Tape Player

54A-54

B. RADIO

B-1 No power is supplied when the switch is set to ON.

Is dedicated fuse No. 6 blown or is the circuit open?

Yes

Replace fuse or repair harness.

Is the connector at the back of the radio connected properly?

Connect connector securely.

Yes

Disconnect and check the connector at the rear of the radio. Is
the ACC power (12 V) being supplied to the radio?

Repair harness.

Yes

Repair or replace radio.

B-2 No sound from one speaker.

Check to see if there is any sound when
attached to another radio.

Yes

Repair or replace radio.

Remove the connector on the back of
the radio and check the speaker har-
ness for conductance.

Yes

It conducts electricity but is shorted out.

Repair speaker harness.

Check the speaker for conductance.

Yes

Repair speaker harness and ensure
proper connection of relay connectors.

Repair or replace speaker.

CHASSIS ELECTRICAL –

Radio and Tape Player

54A-55

B-3 There is noise but no reception for FM/MW/LW or no sound from FM/MW/LW.

Is the check being conducted under
special electrical field conditions?

Yes

Example: In an underground
garage or inside a building.

Does tuning solve the problem?

Is proper performance obtained when
the vehicle is moved?

Yes

Reconnect

Are the antenna plug and radio unit properly connected?

Yes

Repair or replace radio.

Yes

Does the problem disappear if connected to another radio?

Replace the antenna.

B-4 Insufficient sensitivity.

Replace the antenna.

Yes

Repair or replace radio.

Yes

Does the problem disappear when a different radio is
connected?

Is the check being conducted under
special electrical field conditions?

Yes

Example: In an underground
garage or inside a building.

Does tuning solve the problem?

Is proper performance obtained when
the vehicle is moved?

Yes

Electrical field condition related

Yes

Is the problem limited to the reception of a specific radio
station from a specific position?

Ensure proper connection.

Is the antenna plug properly connected to the unit?

Content .. 332 333 334 335 ..