When checking for continuity in a circuit, what is a crucial first step?

When checking for continuity in a circuit, the crucial first step is to disconnect power from the circuit. This is essential for safety reasons, as measuring continuity while the circuit is energized can lead to inaccurate readings and poses a risk of electric shock. Ensuring that the circuit is de-energized allows the technician to safely use a multimeter or continuity tester to check for the presence of a complete electrical path without the risk of electric current flowing through the circuit.

Isolating the circuit by switching off power avoids potential damage to the testing equipment and the technician. Once the power is disconnected, one can confidently ensure that the circuit components and connections are functioning correctly by checking continuity without interference from live voltage. This step acts as a foundational practice in maintaining safety standards and adhering to proper diagnostic procedures in residential air conditioning systems and electrical work in general.