2. Remove and check the relay of the electric motor of the heater fan. If the relay is working properly, proceed to point #3, if it is faulty, it should be replaced.
3. Measure the voltage between terminal "1" of the heater fan motor relay connector and ground. If the voltage matches the battery voltage, proceed to step #4; if it does not, check the reliability of the wiring between fuse #5 (40 A) of the relay unit and the heater fan motor relay.
4. Turn the ignition key to the "ON" position.
5. Measure the voltage between terminal "5" of the heater blower motor relay connector and ground. If the voltage matches the battery voltage, proceed to step #6. If the voltage does not match, check the reliability of the wiring between fuse #20 (7.5 A) of the fuse box and the heater blower motor relay.
6. Turn the ignition key to the "OFF" position.
7. Check the continuity between terminal "3" of the heater fan motor relay connector and ground. If there is continuity, proceed to step #8; if there is no continuity, repair the open circuit in the ground circuit "G402".
8. Install the heater fan motor relay.
9. Disconnect the heater fan motor connector.
10. Turn the ignition key to the "ON" position.
11. Measure the voltage between terminal "1" of the heater fan motor connector and ground.
If the voltage matches the battery voltage, proceed to step #12; if it does not, repair the open circuit between the heater fan motor relay and the heater fan motor.
12. Turn the ignition key to the "OFF" position.
13. Connect the heater motor connector.
14. Short the terminal "2" of the heater fan motor connector to ground.
15. Turn the ignition key to the "ON" position. If the fan rotates, proceed to step #16, if it does not rotate, replace the heater fan motor.
16. Turn the ignition key to the "OFF" position and disconnect terminal "2" of the heater fan motor connector from ground.
17. Disconnect the heater blower resistor connector.
18. Turn the ignition key to the "ON" position.
19. Measure the voltage between terminal "2" of the heater fan resistor connector and ground. If the voltage matches the battery voltage, proceed to step #20; if not, repair the open circuit in the wires between the heater fan motor, the heater fan resistor, and the heater fan speed switch.
20. Turn the ignition key to the "OFF" position.
21. Disconnect the heater fan speed switch connector.
22. Check the conductivity between terminal "3" of the heater fan speed switch connector and ground.
If there is continuity, the heater fan speed switch should be replaced. If there is no continuity, repair the open circuit in the ground circuit "G402".
(Refer to the original source on the website: www.HondaBook.ru)