Mitsubishi 380. Manual - part 920

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-214

STEP 3. Check that noise appears when the radio switch is 
turned on while the vehicle is stopped.

NOTE: Body static electricity from the shock absorber rubber 
bushings used to prevent vibration, tyres, etc. occurs because 
of separation from the ground, causing a buzzing noise. There 
is no measures to discharge the static electricity of the vehicle 
body. Check that there is no noise.

Q: Does noise appear when the radio switch is turned on 

while the vehicle is stopped and the radio is tapped 
while tuned away from a station?
YES : Go to Step 4.
NO :  It may be static electricity noise.

STEP 4. Verify that the radio is correctly grounded.

Q: Is the radio correctly grounded?

YES : Go to Step 5.
NO :  Check that there is no noise.

STEP 5. Check by replacing radio and CD player or radio, 
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player 

and CD changer work normally?
YES : Either repair or replace the original radio and CD 

player or radio, CD player and CD changer. Check 
that there is no noise.

NO :  Either repair or replace the antenna assembly. Check 

that there is no noise.

INSPECTIONPROCEDURE 14: Constant Noise.

DIAGNOSIS

.

Use the Symptom Chart to diagnose the possible cause(s) of 
the noise. Noise is often created by the following factors:

• Travelling conditions of the vehicle

• Terrain of area travelled through

• Surrounding buildings

• Signal conditions

• Time period

If there are still problems with noise, even after performing 
inspection procedures 8 to 15, obtain information on the factors 
listed above. Determine whether the problem occurs on AM or 
FM, the station names, frequencies, etc. and contact the radio 
manufacturer's service centre.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-215

INSPECTION PROCEDURE 15: No reception (AM).

DIAGNOSIS

.

STEP 1. Check to see if inspections are taking place is an 
area exposed to special electric fields.

Q: Are inspections taking place under special electric field 

conditions? (underground garage, inside a building, 
etc.)?
YES : Go to Step 2.
NO :  Go to Step 3.

STEP 2. Move the vehicle and check the radio.
Move the vehicle to a good reception area that is not exposed 
to special electric fields.

Q: Is reception of the strongest radio frequency possible 

within the area?
YES : There is no action to be taken.
NO :  Go to Step 3.

STEP 3. Tune the radio, and then check it.

Q: Did the sensitivity improve after tuning?

YES : There is no action to be taken.
NO :  Go to Step 4.

STEP 4. Check the connection of the antenna plug and 
radio and CD player or radio, CD player and CD changer.

Q: Is the antenna plug thoroughly connected to the radio 

and CD player or radio, CD player and CD changer?
YES : Go to Step 5.
NO :  Thoroughly connect the antenna plug and the radio 

and CD player or radio, CD player and CD changer. 
The radio should sound normally.

STEP 5. Check by replacing radio and CD player or radio, 
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player 

and CD changer work normally?
YES : Either repair or replace the original radio and CD 

player or radio, CD player and CD changer. The radio 
should sound normally.

NO :  Either repair or replace the antenna assembly. The 

radio should sound normally.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-216

INSPECTION PROCEDURE 16: Poor Reception.

DIAGNOSIS

.

STEP 1. Check to see if inspections are taking place is an 
area exposed to special electric fields.

Q: Are inspections taking place under special electric field 

conditions? (underground garage, inside a building, 
etc.)?
YES : Go to Step 2.
NO :  Go to Step 3.

STEP 2. Move the vehicle and check the radio.
Move the vehicle to a good reception area that is not exposed 
to special electric fields.

Q: Is reception of the strongest radio frequency possible 

within the area?
YES : Check that a poor reception is resolved.
NO :  Go to Step 3.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-217

STEP 3. Tune the radio, and then check it.

Q: Did the sensitivity improve after tuning?

YES : Check that a poor reception is resolved.
NO :  Go to Step 4.

STEP 4. Check with several broadcasting stations.

NOTE: Two types of noise are addressed in this procedure, 
multipath and fading noise. The frequency of FM waves is 
extremely high. This makes them susceptible to effects from 
geological formations and buildings. These effects disrupt the 
broadcast signal and obstruct reception in many ways.

.

• Multipath noise is the echo that occurs when the broadcast 

signal is reflected by a large obstruction and enters the 
receiver with a slight time delay relative to the direct signal 
(repetitious buzzing).

• A fading or buzzing noise may occur when the broadcast 

beam is disrupted by obstructing objects and the signal 
strength fluctuates within a narrow range.

Q: Is the abnormality in reception generated only within a 

certain range?
YES : Check that a poor reception is resolved.
NO :  Go to Step 5.

STEP 5. Check the connection of the antenna plug and 
radio and CD player or radio, CD player and CD changer.

Q: Is the antenna plug thoroughly connected to the radio 

and CD player or radio, CD player and CD changer?
YES : Go to Step 6.
NO :  Thoroughly connect the antenna plug and the radio 

and CD player or radio, CD player and CD changer. 
Check that a poor reception is resolved.

STEP 6. Check by replacing radio and CD player or radio, 
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player 

and CD changer work normally?
YES : Either repair or replace the original radio and CD 

player or radio, CD player and CD changer. Check 
that a poor reception is resolved.

NO :  Either repair or replace the antenna assembly. Check 

that a poor reception is resolved.