How Do a Car's Dash Lights Work?

Car Dashboard Lights Fulfill a Basic Function

Car dash lights are simple low-grade lights that work to illuminate the various dashboard instruments and gauges on a car. Although vehicle dashboards vary tremendously, they all use basic dashboard lights to make the various gadgets, dials, and accessories readable at night.

Manually Operated Lights

All dashboard lights in cars are manually operated. As a safety feature, dashboard lights are wired to turn on when a car's headlights are turned on. When a driver pulls or presses the headlight switch, the dashboard lights are wired to come on. However, most cars allow for the driver to switch off, or adjust the brightness of, the dashboard lights after they come on. This is normally done by manually turning the headlight knob switch, or the car may feature a rheostat dial on the dash itself.

Electrical Connections/Fuses

Dashboard lights are made up of simple electrical connections. All electricity in a car originates from the car battery and is transported to various locations via a web of interconnected wires, fuses, and relays. A car's dashboard lights have small bulbs that are supplied with electricity from several small-grade wires. Fuses, which are an electrical safety feature, blow out whenever there is a short or electrical overload. Non-functioning dashboard lights are normally caused by blown fuses, which can easily be replaced in minutes.