Inspection Procedure 5

Blower Fan and Motor does not Turn.

Blower Motor Circuit Part 1:

Blower Motor Circuit Part 2:

TECHNICAL DESCRIPTION (COMMENT)
If the blower fan and motor does not turn when the blower switch is operated, the blower switch may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the blower relay
- Malfunction of the blower switch
- Malfunction of the blower motor
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set

STEP 1. Check that the blower motor operates when the blower switch is moved to the "4 (HI) " position.

1. Turn the ignition switch to the "ON" position.
2. Turn the blower switch to the "4 (HI) " position.

Q: Does the blower motor operate when the blower switch is moved to the "4 (HI) " position?

YES : Refer to Inspection procedure 6 "Blower air amount cannot be changed."

NO : Go to Step 2.




STEP 2. Check blower motor connector C-13 for damage.

Q: Is blower motor connector C-13 in good condition?

YES : Go to Step 3.

NO : Repair or replace the connector. Refer to Harness Connector Inspection. The blower motor should operate normally.

STEP 3. Measure the resistance at blower motor connector C-13.




1. Disconnect blower motor connector C-13, and measure the voltage at the wiring harness side.




2. Measure the resistance value between terminal 2 and ground.
- 2 ohm or less

Q: Does the measured resistance value correspond with this range?

YES : Go to Step 5.

NO : Go to Step 4.




STEP 4. Check the wiring harness between blower motor connector C-13 (terminal 2) and ground.

Q: Is the wiring harness between blower motor connector C-13 (terminal 2) and ground in good condition?

YES : The blower motor should operate normally.

NO : Repair the wiring harness. The blower motor should operate normally.

STEP 5. Measure the voltage at blower motor connector C-13.




1. Disconnect blower motor connector C-13, and measure the voltage at the wiring harness side.
2. Turn the ignition switch to the "ON" position.
3. Turn the blower switch to the "HI" position.




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

Q: Does the measured voltage correspond with this range?

YES : Go to Step 18.

NO : Go to Step 6.




STEP 6. Check blower relay connector C-217 for damage.

Q: Is blower relay connector C-217 in good condition?

YES : Go to Step 7.

NO : Repair or replace the connector. Refer to Harness Connector Inspection. The blower motor should operate normally.







STEP 7. Check the blower relay continuity.
Follow the table to check the blower relay for continuity.

Q: Is the blower relay continuity in good condition?

YES : Go to Step 8.

NO : Replace the blower relay. The blower motor should operate normally.

STEP 8. Measure the voltage at blower relay connector C-217.




1. Disconnect blower relay connector C-217, and measure the voltage at the junction block side.
2. Turn the ignition switch to the "ON" position.




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

Q: Does the measured voltage correspond with this range?

YES : Go to Step 10.

NO : Go to Step 9.




STEP 9. Check the wiring harness between blower relay connector C-217 (terminal 3) and the ignition switch (IG2).

NOTE: Also check junction block connector C-212. If junction block connector C-212 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower relay connector C-217 (terminal 3) and the ignition switch (IG2) in good condition?

YES : The blower motor should operate normally.

NO : Repair the wiring harness. The blower motor should operate normally.

STEP 10. Measure the resistance at blower relay connector C-217.




1. Disconnect connector C-217, and measure the resistance at the junction block side.




2. Measure the resistance value between terminal 1 and ground.
- 2 ohm or less

Q: Does the measured resistance value correspond with this range?

YES : Go to Step 12.

NO : Go to Step 11.




STEP 11. Check the wiring harness between blower relay connector C-217 (terminal 1) and ground.

NOTE: Also check junction block connector C-215. If junction block connector C-215 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower relay connector C-217 (terminal 1) and ground in good condition?

YES : The blower motor should operate normally.

NO : Repair the wiring harness. The blower motor should operate normally.

STEP 12. Measure the voltage at blower relay connector C-217.




1. Disconnect blower relay connector C-217, and measure the voltage at the junction block side.




2. Measure the voltage between terminal 5 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES : Go to Step 14.

NO : Go to Step 13.







STEP 13. Check the wiring harness between blower relay connector C-217 (terminal 5) and fusible link (1).

NOTE: Also check intermediate connector C-121 and junction block connector C-213. If intermediate connector C-121 or junction block connector C-213 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower relay connector C-217 (terminal 5) and fusible link (1) in good condition?

YES : The blower motor should operate normally.

NO : Repair the wiring harness. The blower motor should operate normally.




STEP 14. Check blower switch connector C-06 for damage.

Q: Is blower switch connector C-06 in good condition?

YES : Go to Step 15.

NO : Repair or replace the connector. Refer to Harness Connector Inspection. The blower motor should operate normally.







STEP 15. Check the wiring harness between blower switch connector C-06 (terminal 2) and blower relay connector C-217 (terminal 4).

NOTE: Also check junction block connector C-212. If junction block connector C-212 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower switch connector C-06 (terminal 2) and blower relay connector C-217 (terminal 4) in good condition?

YES : Go to Step 16.

NO : Repair the wiring harness. The blower motor should operate normally.







STEP 16. Check the blower switch continuity.
Follow the table to check the blower switch for continuity.

Q: Is the blower switch continuity in good condition?

YES : Go to Step 17.

NO : Replace the blower switch. The blower motor should operate normally.







STEP 17. Check the wiring harness between blower motor connector C-13 (terminal 1) and blower switch connector C-06 (terminal 6).

Q: Is the wiring harness between blower motor connector C-13 (terminal 1) and blower switch connector C-06 (terminal 6) in good condition?

YES : The blower motor should operate normally.

NO : Repair the wiring harness. The blower motor should operate normally.




STEP 18. Check the blower fan and motor operation.
When battery voltage is applied between the terminals, check that the motor operates.

Q: Is there any abnormal noise?

YES : The blower motor should operate normally.

NO : Replace the blower relay. The blower motor should operate normally.