RCD Electrical explains how to use a multimeter for accurate electrical fault diagnosis. From checking voltage and continuity to testing resistance and current, our expert guide highlights essential safety and usage tips for domestic and commercial settings. Ignoring this vital. While professional electricians are the best choice for complex repairs, understanding how to perform basic tests on your electrical panel with a multimeter can empower you to diagnose common issues, assess the overall health of your system, and even troubleshoot simple problems. Multimeters are essential tools for. Turn the circular meter knob either clockwise or anti-clockwise to the location specified “OHM” or “Ω” which is meant to measure resistance. Warning: Working with live circuits can be dangerous.