Testable sealed and/or self-diagnosing electromagnetic or solid-state relays simplify troubleshooting of electrical circuits. The testable relay comprises a relay housing with terminals adapted to connect to a circuit and an opposing top wall with testable terminals formed as projections being flush with or extending from the top wall and being exposed for testing the relay by applying a multimeter device. A self-diagnosing relay comprises a relay housing with terminals adapted to connect to a circuit, and at least two light-emitting diodes (LEDs). One of the LED indicates the relay is energized, and another LED light is a diagnostic LED and indicates if the relay is damaged.