Symptoms
- Fog light switch doesn't seem to do anything
- Fog lights worked before but stopped suddenly
- Indicator light for fog lights doesn't illuminate on the dash
- One fog light works but not the other
Likely causes
- CommonFog lights not engaged correctly (headlights required first)Many vehicles require the headlights or parking lights to be on before fog lights can be activated.
- CommonBurned out fog light bulbFog light bulbs can burn out just like any other bulb.
- CommonBlown fog light fuseA dedicated fuse failure will disable both fog lights at once.
- PossibleDamaged wiring or connector, often from road debrisFog lights are mounted low and exposed to road debris that can damage wiring.
What to do
- Make sure headlights or parking lights are on first, since most vehicles require this before fog lights will activate.
- Check the fuse box for a blown fog light fuse and replace with the correct amperage.
- If only one fog light is out, check that bulb first for a burned out filament.
- Access the fog light bulb (often from under the front bumper or through a wheel well access panel) if needed.
- Inspect wiring near the fog lights for damage, since their low mounting position exposes them to road debris.
- Check the fog light switch itself for proper function and clean contacts if it feels unresponsive.
- Test with a new bulb if the old one looks burned out or damaged.
- Have a shop check the wiring harness if fuses and bulbs are fine but fog lights still don't work.
Tools and parts
- Fuse puller or pliers
- Screwdriver (varies by vehicle)
Fog light bulbSearch: “fog light bulb for [your car make model year]”
When to call a pro
If fog lights stopped working after driving through deep water or off-road conditions, have a shop check for water damage to the wiring or bulb sockets.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.