Use Your Multimeter's Resistance Setting to Diagnose a Dead Appliance Part
The Problem
Continuity testing tells you whether current can get through a component at all, but it misses a whole category of failures: parts like heating elements, motor windings, temperature sensors, and fixed resistors fail by drifting out of their correct resistance range while still technically passing continuity. If everything checks out on continuity and the appliance still won't work, that's the sign to test resistance instead.
The Technique
- Fully disconnect the appliance from power — unplug it, don't just switch it off.
- Set the multimeter to its resistance (Ω) setting and pick a range just above what you expect the component to read (most meters step through ranges like 200, 2,000, 20,000, 200,000, and 2,000,000 ohms).
- Touch one probe to each side of the component and read the value.
- Compare the reading to the manufacturer's rated value and tolerance for that part — a heating element rated at 680,000 ohms should read close to that, not exactly on the number.
- Interpret the result: a reading far above spec, or "OL" on the display, usually means an open/broken component; a reading far below spec can mean an internal short. Either way, well outside tolerance means it's time to replace that part.
Pro tip: Resistance testing only tells you something if you know what the part is supposed to read first — look up the manufacturer's spec before you test, not after.
Safety note: Always fully disconnect power before testing resistance. Testing a live circuit with the meter set to ohms can damage the meter and shock you.