What does a voltmeter measure in an automotive electrical system?

A voltmeter is specifically designed to measure the electrical potential difference, or voltage, across different points in an electrical circuit. In the context of an automotive electrical system, this means that a voltmeter can help diagnose issues by showing the voltage level at various components, such as the battery, alternator, or wiring connections. By understanding the voltage levels, technicians can determine if there is adequate power supply and whether components are functioning correctly.

For instance, if a voltmeter reads significantly lower than the expected voltage, it may indicate a problem, such as a weak battery or a poor connection in the wiring. Thus, the ability to measure voltage is critical for maintaining and troubleshooting an automotive electrical system.

In contrast, measuring current is the function of an ammeter, while resistance is measured by an ohmmeter. Temperature measurement is not a function of a voltmeter either, as it plays no role in assessing electrical potential.