When troubleshooting a vehicle’s electrical system, what is the first step?

The first step when troubleshooting a vehicle’s electrical system is inspecting fuses and connections. This step is crucial because many electrical issues stem from blown fuses or poor connections that interrupt the flow of electricity. By starting with a visual inspection of the fuses, a technician can quickly identify if there's a simple solution before moving on to more complex diagnostics.

Inspecting connections, such as wiring harnesses and terminals, helps reveal any loose, corroded, or damaged connections that could cause electrical malfunctions. This foundational step ensures that obvious problems are addressed early, thereby saving time and effort in the troubleshooting process.

Other options, while they may be part of the troubleshooting process, are best utilized after confirming that the basic elements of the electrical system, like fuses and connections, are functioning properly. For instance, using a scanner tool could provide detailed codes and information, but if the issue is due to a blown fuse or poor connection, it may not be effectively diagnosed by just scanning. Similarly, consulting a repair manual is important for guidance, but it is often more practical to start with the physical inspection of components that are frequently at fault in electrical issues. Replacing the battery without first verifying other potential causes could lead to unnecessary expense and effort.