Troubleshooting Motion Sensor Lights

A motion sensor light on a brick home.

Your home's security system often includes exterior motion sensor lighting to provide you and your family a complete level of home security. However, outside elements like weather, sunshine, dirt, and grime can wreak havoc on your equipment. Motion sensor lighting provides an economical way to light walkways, driveways, and areas of concern that require extra security to protect you and your home. When they fail, you can be left without exterior lighting in these areas and that poses a serious problem. If your exterior motion sensor lighting has malfunctioned, there are several things you can do to diagnose the problem and restore service.

Symptoms of a Malfunctioning Motion Sensor Light

Several signs can point to a malfunctioning motion sensor light. The most obvious one is the light fails to come on. Others include a light that stays on all the time or one that fails to detect motion and illuminate correctly.

Inspect the Motion Sensor Lens

A motion sensor light.

The motion sensor lens is subject to extreme abuse from outside elements. These include rain, sunshine, dirt, and insects. The motion sensor itself acts like an eye. When it detects movement, it activates the light fixture. When the motion sensor lens becomes obstructed, dirty or cloudy due to age, it will fail to work properly. Make sure the lens is clean and free of anything that could obstruct its view.

Replacing the Bulb

When your light fails to illuminate, the easiest measure to take is to replace the bulb. If you have a spare on hand great, simply remove the old bulb and install the new one. However, when a replacement is not on hand, you must travel to your local home improvement center or hardware store. Before you embark, you would be wise to remove the bulb in question and take it with you. There are many styles of exterior motion sensor lighting available with a multitude of bulb types. Taking the old bulb with you will ensure you purchase the correct type.

Resetting your Motion Sensor Lights

Often, resetting your motion sensor light will restore service. Simply flipping the on/off switch to the light is not enough. You must locate and identify the circuit breaker supplying the fixture with electricity in the main circuit breaker panel box. The applicable circuit breaker might be labeled as such but often is not. Turn off the applicable circuit breaker for a few minutes and then turn it back on.

Verifying Electricity to the Fixture

A motion sensor light reveals a hooded figure.

A simple voltage meter available at most home improvement centers can verify the fixture is receiving power. Many types of voltage meters are available so it is important to follow the manufacturer's operating instructions and safety measures when using one. With electricity to the fixture turned off, remove the fixture and disconnect its wires by removing the wire nuts connecting it to the circuit wires supplying it with electricity.

Carefully restore power to the circuit wires and test with the voltage meter. If electricity is present, the problem lies within the fixture. If electricity is not present, most likely the problem lies somewhere within the electrical circuit. The particular light fixture in question could be connected with a series of exterior lights and the problem lies within another fixture. At this time, it would probably be a good idea to call a professional.

Bypassing the Motion Sensor

Often, the problem is caused by a faulty motion sensor. You can determine if you have a faulty motion sensor by disconnecting it and wiring the light fixture direct. First, turn off the switch or circuit breaker supplying the fixture with electricity.

Next, remove the fixture cover to expose its wires. Most motion sensors incorporate two sets of wires. One set connects to a power source and the other connects to the light socket. First, disconnect both sets of wires from the motion sensor. Next, connect the two power wires to the wires leading from the light socket. Restore power to the fixture. If it lights up, your motion sensor is bad. When it does not, the problem lies somewhere else in the fixture and it may be time for a complete replacement.

It is important to use extreme caution when working with electricity. A shock hazard exists that can cause serious injury or even death. If you do not have any experience working with electricity, or have some experience but are uncomfortable or apprehensive, it is best to call a licensed professional.