Oil Pressure Switch Test

Disconnect the oil pressure switch connector (A) from the oil pressure switch (B).

Fig 1: Identifying Oil Pressure Switch Connector, Switch Terminal And Oil Pressure Switch
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between the oil pressure switch terminal (C) and the engine (ground). There should be no continuity with the engine stopped. There should be continuity with the engine running.