3 Steps to Test an Extension Cord With a Multimeter

Set your multimeter to resistance (ohms) or continuity mode. The cord must be unplugged with no load attached before testing.

Check for shorts by testing hot to neutral, hot to ground, and neutral to ground. Each should read infinite resistance (OL). A low reading or beep means a short or ground fault—toss the cord.

Confirm continuity by testing each plug pin to its corresponding socket pin. A near-zero resistance or beep means the wire is intact. Infinite resistance means a broken wire inside—toss the cord.