Disconnect the radiator fan switch 2P connector. Turn the ignition switch ON (II). Measure voltage between the No. 2 terminal of the radiator fan switch 2P connector and body ground. RADIATOR FAN SWITCH 2P CONNECTOR Is there battery voltage? YES - Go to step 4. NO - Repair open in the wire between the radiator fan switch 2P connector terminal No. 2 and under-hood fuse/relay box. Turn the ignition switch OFF, and check for continuity between the No. 1 terminal of the radiator fan switch 2P connector and body ground. RADIATOR FAN SWITCH 2P CONNECTOR Is there continuity? YES - Replace the radiator fan switch. NO - Check for an open in the wire between the radiator fan switch 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.

Remove the radiator fan relay from the under-hood fuse/relay box and test it, refer to the 2001 Civic Shop Manual (see page 22-80). Is the relay OK? YES - Go to step 2. NO - Replace the radiator fan relay. Remove the radiator fan switch, and test it (see page 10-17). Is the radiator fan switch OK? YES - Go to step 3. NO - Replace the radiator fan switch. Disconnect ECM connector B (24P) and the under-hood fuse relay box 14P connector. Check for continuity between the No. 2 terminal of the radiator fan switch 2P connector and body ground. RADIATOR FAN SWITCH 2P CONNECTOR Is there continuity? YES - Repair short in the wire between the radiator fan switch 2P connector terminal No. 2 and under-hood fuse/relay box. NO - Replace the under-hood fuse/relay box. aaa