The courtesy lamp assembly is the complete unit of all of the components that make up a courtesy lamp. Parts usually include the bulb, the lamp base, a lens to cover the bulb and a switch to turn the light on. Wires are then attached to the courtesy lamp assembly in order to fit it to the vehicle’s power supply.

Courtesy lights are found in the interior of the vehicle, sometimes in the front or rear of the roof in the passengers seating area or in the door area in the rear. There are however, some vehicles, such as the Volvo that have courtesy lamp assemblies in the driverside floor of the vehicle. These are more prone to wear due to their location and are more likely to need replacement than courtesy lamp assemblies situated in other parts of the vehicle.

Failure of the courtesy lamp assemblies can be caused by simple means such as a blown bulb but should be investigated further in case the issue is caused by damage to the wiring of the lighting system. Another part of the assembly that may fail is the light switch.