Inspection Procedure 6

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 Tool:
- MB991223: Test Harness Set




STEP 1. Check blower motor connector C-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is blower motor connector C-08 in good condition?

YES: Go to Step 2.

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

STEP 2. Measure the voltage at blower switch connector C-08.




1. Disconnect blower switch connector C-08, 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 "4 (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 15.

NO: Go to Step 3.




STEP 3. Check blower relay connector C-216 for damage.

Q: Is blower relay connector C-216 in good condition?

YES: Go to Step 4.

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







STEP 4. 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 5.

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

STEP 5. Measure the voltage at blower relay connector C-216.




1. Disconnect blower relay connector C-216, 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 7.

NO: Go to Step 6.




STEP 6. Check the wiring harness between blower re connector C-216 (terminal 3) and the ignition switch (IG2).

NOTE: Also check junction block connector C-211. If junction block connector C-211 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower relay connector C-216 (terminal 3) and the ignition switch (IG2) in 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 the wiring harness. The blower motor should operate normally.

STEP 7. Measure the resistance at blower relay connector C-216.




1. Disconnect connector C-216, and measure the resistance at the junction block side.




2. Measure the resistance value between terminal 1 and ground.
- The measured value should be 2 ohms or less.

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

YES: Go to Step 9.

NO: Go to Step 8.




STEP 8. Check the wiring harness between blower relay connector C-216 (terminal 3) and ground.

NOTE: Also check junction block connector C-214. If junction block connector C-214 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower relay connector C-216 (terminal 3) and ground 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 the wiring harness. The blower motor should operate normally.

STEP 9. Measure the voltage at blower relay connector C-216.




1. Disconnect blower relay connector C-216, 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 11.

NO: Go to Step 10.







STEP 10. Check the wiring harness between blower relay connector C-216 (terminal 5) and fusible link (1).

NOTE: Also check intermediate connector C-126 and junction block connector C-212. If intermediate connector C-126 or 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-216 (terminal 5) and fusible link (1) 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 the wiring harness. The blower motor should operate normally.




STEP 11. Check blower switch connector C-125 for damage.

Q: Is blower switch connector C-125 in good condition?

YES: Go to Step 12.

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







STEP 12. 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 13.

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







STEP 13. Check the wiring harness between blower switch connector C-125 (terminal 2) and blower relay connector C-216 (terminal 4).

NOTE: Also check junction block connector C-211. If junction block connector C-211 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between blower switch connector C-125 (terminal 2) and blower relay connector C-216 (terminal 4) in good condition?

YES: Go to Step 14.

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







STEP 14. Check the wiring harness between blower switch connector C-125 (terminal 6) and blower motor connector C-08 (terminal 1).

Q: Is the wiring harness between blower switch connector C-125 (terminal 6) and blower motor connector C-08 (terminal 1) 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 the wiring harness. The blower motor should operate normally.

STEP 15. Measure the resistance at blower motor connector C-08.




1. Disconnect blower motor connector C-08, and measure the voltage at the wiring harness side.




2. Measure the resistance value between terminal 2 and ground.
- The measured value should be 2 ohms or less.

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

YES: Go to Step 17.

NO: Go to Step 16.




STEP 16. Check the wiring harness between blower motor connector C-08 (terminal 2) and ground.

Q: Is the wiring harness between blower motor connector C-08 (terminal 2) and ground 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 the wiring harness. The blower motor should operate normally.




STEP 17. 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: 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: Replace the blower relay. The blower motor should operate normally.