Is the relay OK?
Yes Proceed to p. 2.
No Replace the radiator fan relay.
2. Remove the radiator fan switch and test it.
Is the radiator fan switch working properly?
Yes Proceed to p. 3.
No Replace the radiator fan switch.
3. Disconnect the cable from the negative battery terminal.
4. Disconnect the ECM/PCM 24-pin connector B and the underhood fuse/relay box 14-pin connector.
5. Check for continuity between terminal No. 2 of the 2-pin radiator fan switch connector and ground.
Is there conductivity?
Yes Repair short circuit in wire between terminal #2 of 2-pin radiator fan switch connector and underhood fuse/relay box.
No Replace the under hood fuse/relay box.
Based on materials from the website: HondaBook.ru