Why Exterior Lighting Deserves Its Own Routine Check
Most drivers notice a headlight failure only when another motorist flashes them at night. Brake lights and reversing lights are even harder to spot because they sit behind you. Yet a single failed bulb can create a real hazard — and in most U.S. states, it is also a ticketable violation.
The good news is that checking every exterior light on your vehicle takes fewer than ten minutes and requires nothing more than your smartphone. This check pairs naturally with the weekly walk-around inspection and complements the monthly tyre and brake safety checks that keep your car roadworthy between service visits.
Lighting Faults Can Be a Legal Issue
In most U.S. states, driving with a non-functioning headlight, brake light, or turn signal is a traffic violation and can result in a fine. A failed light can also void an insurance claim if it contributed to a collision. Check your lights regularly and address any failures promptly.
Before you begin, gather what you need.
What you will need
How to Check Every Light Solo — Step by Step
The steps below cover all primary exterior lights in a logical sequence, moving from front to rear. You do not need a second person — the smartphone camera method is reliable and takes no technical skill.
Smartphone
Use the camera to view brake lights and reversing lights that you cannot see directly from the driver's seat.
Reflective surface (garage door or window)
Provides a mirror-like view of rear lights when no assistant is available.
Owner's manual
Identifies the correct replacement bulb type and location for each light fitting.
Park safely and prepare your phone
Park on a flat surface — ideally facing a garage door, large window, or pale wall that can act as a reflective surface for rear-light checks. Set your smartphone to camera mode and place it within easy reach. Make sure the engine is running and the ignition is fully on.
Check headlights — low beam and high beam
Switch on your headlights and walk to the front of the vehicle. Verify that both low-beam headlights are lit and evenly matched in brightness and colour. Return to the cabin, switch to high beam, and check again. A noticeably dimmer or yellowish lens on one side often signals a failing bulb, even if it is still lit.
Check front indicators (turn signals)
With the engine running, switch on your left indicator and walk to the front-left corner to confirm it is flashing at a normal, steady rate. Repeat for the right indicator. An unusually fast flash rate — often called hyper-flashing — typically means the bulb on that side has burned out or is close to failure.
Check rear indicators and tail lights
Move to the rear of the car. If you have a reflective surface behind you, position your phone so the camera faces the rear lights. Switch on your left indicator and watch the reflection or phone screen for a steady flash. Repeat for the right. Then switch to parking lights (sidelights) and confirm both rear tail lights glow with equal brightness.
Check brake lights
This is the light most drivers miss because you cannot see it from the driver's seat. Position your smartphone camera facing the rear of the car, or use the reflective surface. Then press the brake pedal firmly — most vehicles have a third, centre-mounted brake light in addition to the two main ones. Confirm all three illuminate. A helper makes this step easier, but the camera method works well solo.
Check the reversing (backup) light
With your camera or reflective surface still in position, put the vehicle in reverse while keeping your foot on the brake. The reversing light — typically white and located at the rear — should illuminate immediately. Shift back to park or neutral once confirmed. A failed reversing light makes low-speed manoeuvring in parking lots significantly more hazardous for pedestrians behind you.
Note any failures and take action
If any light failed the check, consult your owner's manual for the correct bulb specification. Many exterior bulbs are straightforward to replace at home, but if a dashboard warning light is also present, or if the problem reappears after replacement, have the vehicle inspected by a qualified mechanic. For general guidance on which checks are safe to do yourself, see when to check it yourself and when to call a mechanic.
Make It a Monthly Habit
Pair your lighting check with another routine task — refuelling, a tyre pressure check, or the weekly walk-around inspection — so it never gets forgotten. Consistency is the simplest form of vehicle safety.
Dashboard Warning Light? Don't Just Swap the Bulb
If a warning light on your dashboard appears alongside a lighting failure, the cause may be electrical rather than a simple burned-out bulb. In that case, have the vehicle inspected by a qualified mechanic before driving. See what dashboard warning lights actually mean for guidance on which symbols need immediate attention.
What to Do After the Check
A clean check with all lights functioning means you can drive with confidence. If you identified one or more failures, consult your owner's manual for bulb specifications. Many standard bulbs — such as turn-signal or tail-light bulbs — are widely available and simple to swap. Replacement instructions are usually in the manual or available from your vehicle manufacturer's support resources.
If a light failure shows up on a used car you are evaluating, treat it as an indicator of broader maintenance habits. The inspection mistakes that cost buyers later article outlines how small oversights during a pre-purchase check can lead to expensive surprises. For a broader view of exterior and mechanical checks worth doing on any used vehicle, the Inspecting Used Cars hub is a practical starting point.
Done monthly, a ten-minute lighting check is one of the simplest habits that keeps you — and other road users — safer.
The content on this site is for informational purposes only and is not a substitute for professional advice. Always consult a qualified professional for guidance specific to your situation.