Uploaded September 2026 | Updated September 2026, 14 hours ago

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Not sure which wire is positive or negative?

In this video, I show how to identify DC wire polarity using a multimeter—even when the wires don't use the usual red and black colors.

This can be useful when working with USB cables, DC cables, and other low-voltage wiring.

⚠️ **SAFETY:** This demonstration is for low-voltage DC only. Do not use exposed-wire testing methods on household 120V AC power. Always use properly rated equipment and follow appropriate electrical safety procedures.

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#ElectricalTips #WirePolarity #DIYElectronics #ElectronicsRepair #Tech #DIY #HowTo #MultimeterTutorial #USB #DCVoltage