If your headlights do not switch from low to high beam, your visibility on dark roads is reduced, especially when driving at higher speeds. This can be caused by faulty bulbs, a bad dimmer switch, wiring issues, or a malfunctioning relay. An assessment will identify the cause and restore proper headlight operation.

What does it mean if headlights don’t change from low to high beam?

This usually indicates an issue with the high-beam circuit, the multifunction/dimmer switch, or the headlight relay. It may also mean the bulbs themselves have failed or are not the correct type for your vehicle.

Common causes of headlights not switching to high beam

• Blown or incorrect headlight bulbs
• Faulty dimmer or multifunction switch
• Failed headlight relay or fuse
• Damaged or corroded wiring/connectors
• Faulty headlight control module (in modern vehicles)

Why do you need to fix this problem quickly?

High beams are essential for night driving on unlit roads. If they don’t work, your ability to spot hazards and react in time is reduced, making driving unsafe.

How do you know when to get it checked?

You should book an inspection if:

• High beams don’t turn on when activated
• Only one headlight switches to high beam
• The high-beam indicator on the dash does not illuminate
• The headlights flicker when switching between low and high beam
• Other lighting issues occur at the same time

What happens during an assessment?

A mechanic will:

1. Test the bulbs, fuses, and relays for proper function
2. Inspect the dimmer/multifunction switch
3. Check wiring and connectors for damage or corrosion
4. Test the headlight control module if applicable
5. Replace faulty components and confirm proper beam switching

How much does it cost to fix?

Bulb or fuse replacement typically costs $50–$120. Relay or switch replacement may cost $150–$400. If a control module is required, costs can rise to $500–$1,200+.

Is it unsafe to drive if headlights won’t switch to high beam?

Yes. Driving without high beams significantly reduces visibility on dark or rural roads, increasing accident risk. This issue should be inspected and repaired promptly.