Before doing anything, first make sure you've got good batteries in it . I always start with a continuity test before doing anything else .
Do this by setting the meter to the lowest "Ohms"setting and touch the probes together...the meter should beep or jump to zero ohms reading.
At that point you know you've got good cables and probes.
I advise you If u don't know how to use a multimeter, don't try to learn on energized live circuits. Watch a few videos as stated above, make sure you understand what you're doing lest u damage the meter , short the equipment or injure yourself.
To check for 110 VAC or 220 VAC , set it for "Volts AC" (VAC) , the meter may be labeled V~ , then set it to a range that what you're testing falls into.
Basically you don't test for 220 vac on the 0-30 VAC setting . Then hold the probes across the terminals or outlet.
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Ohms symbol, meter reades "open circuit" , infinite ohms
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Doing a Continuity test, meter reads almost zero ohms, little to no resistance
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AC volts symbol, for 110vac or 220vac
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DC Volts symbol