Turn Signal Relay and Hazard Flasher

How Do Hazard Lights Work?

Hazard lights, also called emergency flashers, are lighting components in your vehicle used in roadside emergencies. These light bulbs are often built into your headlight, tail light, or turn signal assemblies. Your vehicle's hazard lights and turn signal bulbs typically operate by using the same wiring circuits but have separate relays and are activated by two different switches. Your hazard light control switch, which is typically located on your dash or on your steering column, allows you to easily turn the hazard lights on when needed. When you activate your vehicle's hazard flashers, all four turn signals begin blinking rapidly in a synchronized pattern and are powered by a relay that sends current to all four hazard light bulbs. Turn signals operate on a separate circuit that allows the turn signals to be activated one side at a time. If you notice your turn signal or hazard light bulbs not illuminating when the switch is turned on, if the bulbs appear dimmer than usual, or if they begin rapidly blinking, you should check the fuse connections in your vehicle's fuse box and the condition of the bulbs themselves. If your fuses are all intact, and if the bulbs are not burned out or damaged, it might be time to replace a damaged relay, corroded socket, or worn or damaged wire. Visit O'Reilly Auto Parts to find the hazard light bulb and turn signal bulb replacements you need to keep the lighting systems on your vehicle working at their best.