Honda Civic. Manual — part 764

K20Z3 engine (see ECM REPLACEMENT ).

NO - Repair open in the wire between the radiator fan relay and the
ECM/PCM.

19. Turn the ignition switch to LOCK (0).
20. Disconnect the jumper wire.
21. Reinstall the radiator fan relay.
22. Disconnect the radiator fan 2P connector.
23. Turn the ignition switch ON (II), then set the A/C button and fan control dial

ON.

24. Measure the voltage between the radiator fan 2P connector terminal No. 2 and

body ground.

Fig. 48: Measuring Voltage Between Radiator Fan 2P Connector Terminal
No. 2 And Body Ground

Is there battery voltage?

YES - Go to step 23.

NO - Repair open in the wire between the radiator fan relay and the radiator
fan.

25. Set the A/C button and fan control dial OFF, then turn the ignition switch to

LOCK (0).

26. Reconnect the radiator fan 2P connector.
27. Connect the radiator fan 2P connector terminal No. 1 to body ground with a

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

jumper wire.

Fig. 49: Connecting Radiator Fan 2P Connector Terminal No. 1 To Body
Ground With Jumper Wire

28. Turn the ignition switch ON (II), then set the A/C button and fan control dial

ON.

Does the radiator fan run?

YES - Go to step 27.

NO - Replace the radiator fan motor, R18A1 engine (see RADIATOR AND
FAN REPLACEMENT ), K20Z3 engine (see RADIATOR AND FAN
REPLACEMENT ).

29. Set the A/C button and fan control dial OFF, then turn the ignition switch to

LOCK (0).

30. Disconnect the jumper wire.
31. Remove the fan control relay from the under-hood relay box, and test it (see

REMOVAL AND INSTALLATION ).

Is the relay OK?

YES - Go to step 30.

NO - Replace the fan control relay.

32. Turn the ignition switch ON (II), then set the A/C button and fan control dial

ON.

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

33. Measure the voltage between the fan control relay 5P socket terminal No. 1

and body ground.

Fig. 50: Measuring Voltage Between Fan Control Relay 5P Socket
Terminal No. 1 And Body Ground

Is there battery voltage?

YES - Go to step 32.

NO - Repair open in the wire between the radiator fan and the fan control
relay.

34. Set the A/C button and fan control dial OFF, then turn the ignition switch to

LOCK (0).

35. Disconnect the A/C condenser fan 2P connector.
36. Check for continuity between the fan control relay 5P socket terminal No. 4

and the A/C condenser fan 2P connector terminal No. 2.

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

Fig. 51: Checking Continuity Between Fan Control Relay 5P Socket
Terminal No. 4 And A/C Condenser Fan 2P Terminal No. 2

Is there continuity?

YES - Go to step 35.

NO - Repair open in the wire between the fan control relay and the A/C
condenser fan.

37. Check for continuity between the A/C condenser fan 2P connector terminal

No. 1 and body ground.

Fig. 52: Checking Continuity Between A/C Condenser Fan 2P Connector
Terminal No. 1 And Body Ground

Is there continuity?

YES - Replace the A/C condenser fan motor, R18A1 engine (see RADIATOR
AND FAN REPLACEMENT ), K20Z3 engine (see RADIATOR AND FAN
REPLACEMENT ).

NO - Check for an open in the wire between the A/C condenser fan and body
ground. If the wire is OK, check for poor ground at G301 (see CONNECTOR
TO HARNESS INDEX ).

38. Turn the ignition switch to LOCK (0).
39. Remove A/C diode A from the under-hood fuse/relay box.
40. Using the diode setting on a DVOM, check for current flow in both directions

between the A/C diode A terminals No. 1 and No. 2.

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)