What is automatic high beam assist?
Reviewed by the Skyview Auto Glass technical team — NWRD-, ASE- and DINITROL-trained technicians · Updated November 2026
Quick answer
Automatic high beam assist switches the high beams on and off for you based on traffic and light. A camera or light sensor behind the windshield, near the rearview mirror, watches for headlights and taillights. Keep the glass in front of that sensor clean and unobstructed, or the feature may not switch correctly.
How automatic high beams work
A camera or a light sensor behind the windshield, usually near the rearview mirror, watches the road ahead for the headlights of oncoming traffic and the taillights of vehicles ahead. When the road is clear and dark, the system switches the high beams on. When it detects another vehicle’s lights, it dips them back to low beam.
The system needs a clear view through the glass in front of the sensor. Dirt, rain, snow, or a sticker placed over that area can keep the high beams from switching, or leave them on when they should dip. On most vehicles the feature can be switched off with a stalk or dash setting, and the driver can always override it manually.
Where is the auto high beam sensor?
- Behind the windshield, near the rearview mirror, on most vehicles.
- It may share the housing with the rain and light sensor.
- Keep the glass in front of it clean and clear of stickers or mounts.
- A tinted strip or a toll tag placed over the sensor can block its view.
- If the high beams will not switch, clean that area of the glass first.
Why do my auto high beams not work?
Most often the glass in front of the sensor is dirty, wet, or covered by a sticker or mount. Clean the area near the mirror, clear any obstruction, and see if the feature returns. If it stopped after a windshield replacement, the sensor may need reseating — see our guide on how a rain sensor works, since the two often share a housing.
More questions about automatic high beams
How do automatic high beams work?
A camera or light sensor behind the windshield, near the mirror, watches for oncoming headlights and the taillights of vehicles ahead, then switches the high beams on and off for you.
Why do my auto high beams not work?
Usually the glass in front of the sensor is dirty, wet, or blocked by a sticker or mount. Clean the area near the mirror and clear any obstruction. If it stopped after a windshield replacement, the sensor may need reseating.
Where is the auto high beam sensor?
Behind the windshield, near the rearview mirror, often sharing a housing with the rain and light sensor. Keep that area of the glass clean and unobstructed.
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