The courtesy light, also commonly known as the dome light, is the light mounted on the interior of the vehicle, usually near the rearview mirror. The courtesy light uses a bulb that turns on when the vehicle door is opened to provide illumination for the passengers. Some dome lights are wired with a timer that turns them off automatically after a specified amount of time, while others will turn off when the doors are closed. The light provided by the dome light helps the passengers find their belongings and watch their step when entering and exiting the vehicle.
While light provided by the courtesy light bulb is not one critical to the operation of the vehicle, when there is a problem, the interior of the vehicle can be left without light, and can cause inconvenience to yourself or your passengers, especially in low light conditions such as night time or in parking structures. Usually when the courtesy light bulb has an issue, it will produce a few symptoms that can alert the driver of a potential issue that should be serviced.
1. Dome light is dim
One of the first symptoms commonly associated with a bad or failing dome light bulb is a dim dome light. If the dome light bulb becomes worn out it may not be able to shine as brightly as it once did. Usually a dim bulb will continue to get dimmer until it eventually burns out.
2. Flickering light
Another symptom of a possible problem with the courtesy light bulb is flickering. If the light bulb is rapidly flicking that may be a sign that the filament has worn out or become damaged. This is usually also a sign that the courtesy light is near the end of it’s service life.
3. No interior light
Probably the most noticeable symptom of an issue with the courtesy light bulb is a dome or courtesy light that does not function. If the bulb burns out the courtesy light will be unable to provide light, and will have to be replaced in order to restore illumination to the interior of the vehicle.
While the dome light bulb is not one critical to the safety of the vehicle, the illumination it provides does make the driving experience more comfortable and convenient for the passengers. For this reason, if you suspect your courtesy light bulb may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic. They will be able to replace your courtesy light bulb if necessary.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Courtesy Light Bulb and was authored by Ed Ruelas.