Honda Civic. Manual — part 737

Fig. 17: Connecting Power Transistor 4P Connector Terminals No 2 And
4 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

14. Turn the ignition switch ON (II).

Does the blower motor run at high speed?

YES -Go to step 15.

NO -Repair open in the GRN wire between the power transistor and the blower
motor.

15. Turn the ignition switch to LOCK (0).
16. Disconnect the jumper wire.
17. Disconnect the heater control panel 24P connector.
18. Check for continuity between body ground and the heater control panel 24P

connector terminals No. 7 and No. 8 individually.

Fig. 18: Checking Continuity Between Body Ground And Heater Control

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

Panel 24P Terminals No 7 And 8
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair any short to body ground in the wires between the heater control
panel and the power transistor.

NO -Go to step 19.

19. Check for continuity between the following terminals of the heater control

panel 24P connector and the power transistor 4P connector.

CONTINUITY CHECK INDEX

Fig. 19: Checking Continuity Between Heater Control Panel 24P And
Power Transistor 4P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 20.

NO -Repair any open in the wires between the heater control panel and the

24P

4P

7

3

8

1

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

power transistor.

20. Turn the ignition switch ON (II).
21. Measure the voltage between body ground and the heater control panel 24P

connector terminals No. 7 and No. 8 individually.

Fig. 20: Measuring Voltage Between Body Ground And Heater Control
Panel 24P Connector Terminals No 7 And 8
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -Repair short to power in the wires.

NO -Go to step 22.

22. Turn the ignition switch to LOCK (0).
23. Reconnect the heater control panel 24P connector.
24. Test the power transistor (see POWER TRANSISTOR TEST ).

Is the power transistor OK?

YES -Check for loose wires or poor connections at the heater control panel
24P connector and at the power transistor 4P connector. If the connections are
good, substitute a known-good heater control panel, and recheck. If the
symptom/indication goes away, replace the original heater control panel.

NO -Replace the power transistor.

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

25. Turn the ignition switch to LOCK (0).
26. Disconnect the jumper wire.
27. Disconnect the blower motor 2P connector.
28. Turn the ignition switch ON (II).
29. Measure the voltage between the blower motor 2P connector terminal No. 1

and body ground.

Fig. 21: Measuring Voltage Between Blower Motor 2P Connector
Terminal No 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Replace the blower motor.

NO -Go to step 30.

30. Turn the ignition switch to LOCK (0).
31. Remove the blower motor relay from the under-hood fuse/relay box, and test it

(see POWER RELAY TEST ).

Is the relay OK?

YES -Go to step 32.

NO -Replace the blower motor relay.

32. Measure the voltage between the blower motor relay 4P socket terminal No. 1

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)