Learn where to plug your multimeter leads before testing. The black lead goes to COM, the red lead to VΩmA for voltage and resistance or to the 10A port for high current. Putting the red lead in the wrong port on a live circuit can blow the meter's fuse.
Hey, are you new to the trades? Here's something you may not know about meter leads. Before you touch a meter to any circuit, stop and look at the bottom of the meter. The black lead belongs in COM. COM means common. It is your reference lead for almost every test. The red lead normally goes in the VΩmA port for voltage, resistance, continuity, and small milliamp measurements. There is usually another red port marked A or 10A. That port is only for measuring current, and it changes how the meter connects to a circuit. Do not leave the red lead there by habit. On a live voltage circuit, a lead in the wrong port can create a high-current fault and blow the meter fuse. Give each lead a firm push. Check for cracked insulation, loose tips, or a probe that can slip off a terminal. A loose connection can give you a false reading, or put your hand too close to live parts. If you are not sure which port you need, pause and check the meter label first. Leads in the right ports protect the meter and yourself. Now that you know, you can help someone else know.
