Which electrical tool would a technician use to test for the presence of voltage at the headlights?

A technician would use a test light to check for the presence of voltage at the headlights because a test light is specifically designed to indicate whether electrical voltage is present in a circuit. When the probe of the test light touches a live wire, the bulb in the test light will illuminate, confirming that voltage is available. This makes it an effective tool for quickly diagnosing electrical issues in automotive lighting systems.

In contrast, an ammeter is used to measure the flow of current in a circuit, which is different from simply checking for the presence of voltage. A temperature probe is utilized for measuring temperature, not electrical voltage. An ohmmeter measures resistance in a circuit, which does not provide information about voltage. Therefore, the test light is the most appropriate and direct tool for testing the voltage at the headlights.