02 - Inspection Procedure
No Sound.Amplifier Power Supply Circuit:
Connector:
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 and tape player.
DIAGNOSIS
Required Special Tool:
- MB991223: Harness set
STEP 1. Check the amplifier power supply circuit by backprobing.
1. Do not disconnect amplifier connector D-20.
2. Measure the voltages between terminal 2 and ground by backprobing.
3. Measure the voltages between terminal 10 and ground by backprobing.
Q: Are the voltages approximately 12 volts (battery positive voltage)?
YES: Go to Step 4.
NO: Go to Step 2.
STEP 2. Check amplifier connector D-20 for damage.
Q: Is amplifier connector D-20 in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speakers should sound.
STEP 3. Check the harness wires between amplifier connector D-20 and fusible link (4).
NOTE: After inspecting intermediate connector C-89, inspect the wires. If intermediate connector C-89 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Q: Are the harness wires between amplifier connector D-20 and fusible link (4) in good condition?
YES: There is no action to be taken.
NO: Repair them. The speakers should sound.
STEP 4. Check amplifier connector D-20 for damage.
Q: Is amplifier connector D-20 in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speakers should sound.
STEP 5. Check the harness wires between amplifier connector D-20 and ground.
Q: Are the harness wires between amplifier connector D-20 and ground in good condition?
YES: Go to Step 6.
NO: Repair them. The speakers should sound.
STEP 6. Check the DIN cable between amplifier and radio, tape player, CD player and CD auto changer.
Q: Are the DIN cable in good condition?
YES: Repair or replace the amplifier or radio, tape player, CD player and CD auto changer. The speakers should sound.
NO: Repair or replace it. The speakers should sound.