Mike PleziaInside service technician, Clark Associates · Commercial Equipment, HVAC, and Refrigeration professional

Resistance and Continuity

11 Sept 2026 · 2 min

Watch on YouTube

1:38

In this instructional monologue, the speaker walks beginners through using a multimeter’s continuity function. They explain how to locate the continuity symbol—often a speaker icon, sound wave, or diode symbol—usually sharing a position with the ohms setting, and how to toggle the mode. The speaker describes the test mechanism: the meter injects a small current and beeps if the circuit path is complete, indicating intact wires, closed switches, or good fuses; no beep signals a break, corrosion, or an open safety switch. Safety advice emphasizes turning off power before testing, as continuity testing is not for live circuits. The speaker outlines when to choose continuity over resistance measurement—quick yes/no checks such as testing thermostat wires, verifying fuses, or confirming limit/safety switches. They also note the limitation that components designed with resistance (e.g., heater elements) may not beep, which is normal. The talk ends with a concise reminder to touch the probes, listen for the beep, and share the knowledge with others.

Chapters

Hey, are you new to the trades? Here's something you may not know about continuity testing. Look for the little speaker icon on the dial. Sometimes sound waves, sometimes a diode symbol. Often it shares a spot with ohms. Just toggle the mode button. Here's what it does. The meter sends a small current through the path and listens for the result. If it beeps, the path is complete. Wires intact, switch is closed, fuse is good. No beep means something is broken. A cut wire, a corroded connection, a tripped safety switch. And just like ohms, power off first. Always. This is not a live circuit test. So when do you reach for continuity instead of ohms? Anytime you just need a yes or no answer fast. Testing a thermostat wire run for a break. Checking a fuse before you second-guess yourself. Verifying a limit switch or a safety switch actually opens and closes like it should. One thing to remember, this test is for simple paths— wires, switches, fuses— not for something like a heater element. That has resistance on purpose. It might not beep, and that's still normal. Touch the probes. Listen. That's the whole test. Now that you know, you can help someone else know.