Inspection Procedure 10

INSPECTION PROCEDURE 10: 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. Refer to Harness Connector Inspection.







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 2 volts (battery positive voltage).

3. Measure the voltage between terminals 4 and ground.
The measured value should be approximately 2 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).

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. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.

NO: Repair or replace the wiring harness. Refer to Harness Connector Inspection.

STEP 5. Check blower relay connector C-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is blower relay connector C-114 in good condition?

YES: Go to Step 6.

NO: Repair or replace the connector. Refer to Harness Connector Inspection.

STEP 6. Check the wiring harness between blower relay connector C-303 (terminal 3) and blower motor connector C-114 (terminal 2).

Q: Is the wiring harness between blower relay connector C-303 (terminal 3) and blower motor connector C-114 (terminal 2) in good condition?

YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.

NO: Repair or replace the wiring harness. Refer to Harness Connector Inspection.