Symptoms of a Bad or Faulty Trunk Light Bulb

Common signs include that the bulb is either much dimmer or much brighter than usual.

When LED light bulbs were invented, they were expected to replace all standard incandescent bulbs fairly quickly. However, most of the cars, trucks, and SUVs driving on America's roads still have standard bulbs in the trunk of their vehicles. This component is often overlooked in routine service and maintenance, but without it, finding items inside the truck, day and night, would be extremely difficult.

What is a truck light bulb?

Simply put, a trunk light is a standard, small light bulb located on top of your car's trunk. It lights up when the hood or trunk lid is opened and is activated by a series of relay switches that only supply power to this component when the trunk is open. Because of this, the trunk light is one of those rare light bulbs that can last for years as it is rarely used. However, like any standard light bulb, it is susceptible to breakage or wear due to age or, in some cases, impact, which can break the filament inside.

It's pretty easy to know when a light bulb in the trunk is damaged and needs to be replaced; however, there are a few general warning signs that can alert a vehicle driver to a potential problem with this component, so they can take proactive action and replace it before it burns out.

The following are some of the common warning signs that a trunk light bulb problem exists and should be replaced by an experienced mechanic.

Bulb is dimmer than usual

A standard light bulb lights up when electricity passes through the light bulb. An electrical signal travels through a light bulb and a series of electrical filaments light up as energy circulates through the light bulb. In some cases, these filaments can begin to wear out, which can cause the bulb to burn much dimmer than normal. While most car owners don't pay attention to the exact brightness of the trunk light, this warning sign is fairly easy to spot. If you open the trunk and the light is dimmer than usual, take steps to remove and replace the trunk light bulb, or contact your local ASE certified mechanic who can complete this project for you.

Light bulb is brighter than usual

On the other side of the equation, in some situations a light bulb will burn brighter than normal if it begins to wear out. This again has to do with the intermittent flow of electricity inside the lamp as the filaments become brittle, damaged or begin to break. As in the situation above, you can do two things:

• First, change the light bulb yourself, which isn't that hard depending on what car you have and your comfort level by removing the trunk lid cover.
• Second, see a mechanic to replace the light bulb for you. This may be a good idea if you have a newer vehicle where the trunk light is located inside the trunk lid and is difficult to access. An experienced mechanic will have the necessary tools to do the job.

The trunk light is one of the most inexpensive auto parts and one of the easiest to replace on most pre-2000 vehicles. If you notice that your trunk light is dimmer or brighter than usual, or if the bulb is burned out, contact one of our professional mechanics to replace your trunk light.