Inspection Procedure 9

INSPECTION PROCEDURE 9: Blower Motor Power Supply System.

Blower Motor Circuit (Part 1):

Blower Motor Circuit (Part 2):

TECHNICAL DESCRIPTION (COMMENT)
If the voltage is not supplied to the blower motor, the blower relay system may be failed.

TROUBLESHOOTING HINTS
- Malfunction of the ETACS-ECU
- Malfunction of the blower relay
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check blower relay connector C-303 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is blower relay connector C-303 in good condition?

YES : Go to Step 2.

NO : Repair or replace the connector.

STEP 2. Check the blower relay continuity.

Follow the table below to check the blower relay for continuity.







Q: Is the blower relay in good condition?

YES : Go to Step 3.

NO : Replace the rear window defogger relay.

STEP 3. Measure the voltage at blower relay connector C-303.

1. Disconnect blower relay connector C-303, and measure the voltage at the junction block side.







2. Measure the voltage between terminals 1 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).







3. Measure the voltage between terminals 4 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts?

YES : Go to Step 5.

NO : Go to Step 4.

STEP 4. Check the wiring harness between blower relay connector C-303 (terminals 1 and 4) and the fusible link (37).

NOTE: Also check ETACS-ECU connector C-309 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-309 is damaged, repair or replace the connector.

- Check the blower relay power supply line for open circuit.

Q: Is the wiring harness between blower relay connector C-303 (terminals 1 and 4) and the fusible link (37) in good condition?

YES : It can be assumed that this malfunction is intermittent.

NO : Repair or replace the wiring harness.

STEP 5. Check blower relay connector C-115 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is blower relay connector C-115 in good condition?

YES : Go to Step 6.

NO : Repair or replace the connector.

STEP 6. Check the wiring harness between blower relay connector C-303 (terminal 3) and blower motor connector C-115 (terminal 1).

NOTE: Also check ETACS-ECU connector C-315 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-315 is damaged, repair or replace the connector.

- Check the blower motor power supply line for open circuit.

Q: Is the wiring harness between blower relay connector C-303 (terminal 3) and blower motor connector C-115 (terminal 1) in good condition?

YES : It can be assumed that this malfunction is intermittent.

NO : Repair or replace the wiring harness.