What is the first check made for most electrical troubleshooting?

The initial step in most electrical troubleshooting processes is to perform a voltage check of the supply line. This step is crucial because verifying that voltage is present ensures that power is reaching the system components as expected. If there is no voltage, it indicates a potential issue upstream, such as a blown fuse, tripped breaker, or failure in the supply line itself. By confirming the presence of voltage first, a technician can rule out these basic power issues before moving on to examine the load, circuit resistance, or wiring continuity.

Conducting a voltage check prevents unnecessary troubleshooting efforts in areas that may not be the source of the problem. For example, if the load or circuit is checked first and found to be functioning normally while there is no voltage detected, the technician may waste time diagnosing components that are not receiving power at all. Therefore, starting with a voltage check establishes a clear understanding of the power supply to the system and directs the technician toward the appropriate next steps in troubleshooting.