1. The simplest test for the main relay is that the engine starts and runs. If so, then the main relay is functioning correctly.
2. If it is necessary to check the relay, remove it from under the dashboard and disconnect the harness from it.
3. Using the connecting wires, connect "+" (plus) battery with 4 relay outputs for Prelude or 6 for Accord. Connect "-" (minus) battery to relay output 8.
4. Check continuity between relay terminals 5 and 7. If continuity is not present, replace relay.
5. Connect battery + wire to relay terminal 5 and negative wire to terminal 2. Check continuity between relay terminals 1 and 3. If not, replace relay.
6. Connect battery + wire to relay terminal 3 and negative pole to relay terminal 8. Check continuity between relay terminals 5 and 7. If not, replace relay. If continuity is present, the relay has not failed.
7. Reinstall the relay.