2. No Sound. (Vehicles With Amplifier)

Amplifier Power Supply Circuit:

Connectors:

CIRCUIT OPERATION
Power is supplied to the amplifier when the fusible link (4).

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably a faulty amplifier power supply circuit system.

TROUBLESHOOTING HINTS
- Damaged harness wire or connector.
- Damaged DIN cable.
- Malfunction of the amplifier.
- Malfunction of the radio, tape player, CD player and CD auto changer.

DIAGNOSIS
Required Special Tool:
MB991223: Harness set




STEP 1. Check the amplifier power supply circuit.
1. Disconnect amplifier connector D-20 and measure at the harness side.
2. Measure voltage between terminal 2 and ground.
- Voltage should be approximately 12 volts (battery positive voltage)
3. Measure voltage between terminal 10 and ground
- Voltage should be approximately 12 volts (battery positive voltage)
If not approximately 12 volts, go to Step 2.
If approximately 12 volts, go to Step 4.




STEP 2. Check amplifier connector D-20 for damage.
If the amplifier connector D-20 is damaged, repair or replace it. Refer to Harness Connector Inspection. The speakers should sound.
If the connector is in good condition, go to Step 3.













STEP 3. Check the harness wires between amplifier connector D-20 and fusible link (4).

NOTE: After inspecting intermediate connector C-89 and C-92, inspect the wires. If intermediate connector C-89 and C-92 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If the harness wires between amplifier connector D-20 and fusible link (4) are damaged, repair them.
The speakers should sound.




STEP 4. Check the amplifier connector D-20 for damage.
If the amplifier connector D-20 is damaged, repair or replace it. Refer to Harness Connector Inspection. The speakers should sound.
If the connector is in good condition, go to Step 5.




STEP 5. Check the harness wires between amplifier connector D-20 and ground.
If the harness wires between amplifier connector D-20 and ground are damaged, repair them.
The speakers should sound.
If the harness wires are in good condition, go to Step 6.

STEP 6. Check the DIN cable between amplifier and radio, tape player and CD auto changer.
If the DIN cable between amplifier and radio, tape player and CD auto changer is damaged, repair or replace it. The speakers should sound.

If the DIN cable is in good condition, repair or replace the amplifier or radio, tape player, CD player and CD auto changer. The speakers should sound.