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Rear Heater Blower Motor Does Not Operate

Rear Heater Blower Motor Does Not Operate

Circuit diagram





Normal operation of rear heater blower motor
The rear heater blower operates as below:
1. Rear heater main switch is turned ON.
2. Rear heater blower switch is turned ON to make ground circuit.
3. Rear heater blower motor relay is magnetized and closes contact.
4. Battery voltage flows through blower motor and motor operates.


Step 1











1. Check the fuses.
2. If a fuse is burned, check for a short circuit in the wiring harness before replacing it.
3. If the fuses are OK, go to Step 2.

Step 2
1. Disconnect the negative battery cable.
2. Disconnect the rear heater unit connector.








3. Apply battery voltage to terminals a and b and ground terminals c and f.
4. Check whether the rear heater blower motor operates.

Step 3
1. Disconnect the negative battery cable.
2. Disconnect the rear heater unit connector.








3. Check continuity between terminals of the rear heater unit connector.

Step 4
1. Remove the rear heater relay.








2. Check continuity between terminals 3 and 4.
3. If not as specified, replace the relay.
4. If correct, proceed to next sub-step.








5. Apply battery voltage to terminal 1 and ground terminal 2.
Check for continuity between terminals 3 and 4.
6. If correct, the relay is OK. Go to Step 5.
7. If not as specified, replace the relay.

Step 5
1. Remove the rear heater unit case.
2. Remove the rear heater blower motor connector.








3. Apply battery voltage to terminal a and ground terminal b.
4. Check whether the rear heater blower motor operates.

Step 6
1. Turn the ignition switch ON.
2. Turn the rear heater main switch OFF.
3. Turn the rear heater blower switch OFF.








4. Measure the voltage at the terminal-wires of the rear heater unit connector.

Step 7
1. Turn the ignition switch ON.
2. Turn the rear heater main switch ON.
3. Turn the rear heater blower switch OFF.











4. Measure the voltage at the terminal-wires of the rear heater main switch connector.

Step 8
1. Remove the rear heater blower switch.











2. Check continuity between terminals of the switch as shown.
3. If not as specified, replace the rear heater blower switch.
4. If correct, repair the wiring harness. (Rear heater unit-Rear heater blower switch-Body ground)