How can a technician determine if an electrical circuit is functioning properly?

Using a multimeter to measure voltage, current, and resistance is a definitive method for a technician to determine if an electrical circuit is functioning properly. A multimeter provides precise readings that can help identify issues in the circuit, such as open circuits, short circuits, or components that may not be operating within their specified range.

By measuring voltage, a technician can check if the correct voltage is present at various points in the circuit, which indicates whether power is reaching components as designed. Measuring current allows for verification that devices are drawing the appropriate amount of electricity, while measuring resistance helps to assess the condition of components and connections, confirming they are not damaged or degraded. This comprehensive approach with a multimeter provides a clear picture of the circuit's health, making it the most reliable method for diagnostics.

Other methods, such as visual inspections or listening for sounds, may not reveal underlying issues and may lead to incorrect assumptions about the circuit's functionality. Replacing fuses without further testing may mask problems without addressing the root causes. Therefore, using a multimeter is the best practice for accurately diagnosing electrical circuits.