Motion Sensor Light Stays On (8 Quick Fixes)

Motion sensor lights are awesome. You walk into a dark room, and presto! Light. No fumbling for a switch or hoping there’s a nightlight that you can find without stubbing your toes. But if you have a motion sensor light that’s always on? That’s not so awesome.

So what’s the deal?

Motion sensor lights stay on for various reasons. These include being near a naturally occurring source of heat, interference generated by other items sharing the circuit, power outages, incorrect settings, a built-in overriding feature, wear and tear, and a badly installed motion sensor.

Motion sensor lights are the perfect solution for lighting parts of your home that you don’t want to have illuminated all the time. They’re also useful for security purposes as they can detect if someone walks across your yard, even if they’re not on a pathway or in front of your house.

Motion sensor lights perform dutifully when installed correctly. However, certain conditions trigger a failure mode, leading to the motion sensor light coming on and staying on. So, why do motion sensor lights stay on, and how can this failure be fixed?

Motion Sensor Light Stays On

Why Are The Motion Sensor Lights Constantly On?

Motion sensors stay on continuously due to a variety of factors. Your motion sensor light could have been performing virtually flawless until it wasn’t.

Motion sensor lights are smart devices that have integrated circuits that essentially use passive infrared (PIR). Although most people believe the lights detect motion, the truth is that the passive infrared detects temperature differences.

Therefore, once the motion sensor light is installed and power is applied to the unit, it measures the ambient temperature of the surrounding air. Once the sensor has got that locked in, anytime something or someone passes in its path that is different than the surrounding air, sets the device off, which leads to the lights going on.


Incorrect Placement

With motion sensor lights, they are only on when there is motion. The positioning of the sensors necessitates a little forethought. You want your lights to turn on at the proper time, whether they’re inside or outside your house. This implies that your sensors must detect what you want them to when you want them to detect it and not always be on.

Therefore, your motion detector lights will perform better if they are strategically placed. The first thing that you need to check is where you have mounted the device. Suppose the motion sensor light is installed in your backyard and is aimed at naturally occurring sources of heat, like a hot tub, for example. In that case, it could lead to the lights staying on even when they shouldn’t be on.

Anything that changes the temperature or blows out hot air, like a dryer exhaust from a dryer vent, will set the light off because the sensor detects a different temperature than the ambient air. Therefore, the lights will stay on continuously because the motion sensor picks up a continuous flow of warm air from an air vent, dryer vent, or heat-reflecting surface.


Circuitry Interference

Another reason that the motion sensor lights stay on continuously is due to interference generated from fluorescent lights, transformers, or electric motors connected to the same circuit as the motion sensor light.


Override Feature

If you’ve tried moving your light and it still won’t turn off (and there’s no interference), it could be that someone has accidentally activated an override feature that keeps the light on.

A built-in override feature is available on some motion light sensors. The sensor light would remain on until the override function is disabled if the override feature was initially enabled.

Unfortunately, people sometimes accidentally enable the override mechanism without even realizing it. If the light switch was flipped on and off repeatedly several times in a row, the override feature will be activated and will cause the lights to stay on.

Therefore, if you have been trying to figure out which direction is on or off on the switch or have curious kids playing with the switch, the override feature has been mistakenly activated as opposed to your sensor malfunctioning.


Power Outages

Sometimes the motion sensor lights go on and won’t turn off because they’ve been triggered by a power outage in your home. When the lights think they’ve been turned off, they start up again when the power comes back on, even though you haven’t actually turned them off at all.

Power outages can also trigger the override feature as the small fluctuations in the power network can fool the switch into believing it’s been repeatedly switched on and off.


Poor Installation

It’s also possible that someone installed your motion sensor lights incorrectly, which means they won’t work properly until the problem is fixed by a professional electrician!

It could be that the fixture is not properly wired to the junction box, which will lead to the lights constantly staying on.


Wear and Tear

As with most devices, they tend to stop working effectively with age. The light staying on could simply be from the mechanisms no longer being as reliable as it once was due to wear and tear from weather damage over the years.

Dust, dirt, and grime can build up over time, which can cause the sensors to misread their surroundings. If a cleaning doesn’t help, you may need to replace the sensor itself.

Sometimes moisture can get in and cause an issue with the functionality of the sensor as well. If this is happening, it’s best to call an electrician to have it fixed as soon as possible so that you don’t risk any electrical fires.


Incorrect Settings

Motion sensor lights typically have adjustable settings which allow you to adjust how long they stay on after sensing movement and how sensitive they are to movement in general. If these settings are incorrect, then even small movements may cause them to turn on (and stay on) for longer than necessary – or vice versa! To fix this issue, try adjusting these settings until you find what works best

The sensitivity setting on your sensor can make a huge difference in what is detected. Sometimes the sensitivity setting is too high, which will turn on the light for the tiniest of triggers. The detection range in the control setting must be adjusted.

Usually, motion sensor lights stay on for a couple of seconds after the PIR sensor has detected something. However, your light duration settings can be changed, so the light stays on longer. The light may be set at auto-on or a 24/7 control setting. Check the setting and adjust accordingly, whether it is dusk to dawn, custom mode, default settings, or manual mode.


How Long Do Motion Sensor Lights Stay On?

A sensor light usually features a timer that keeps the light on for a specific period after the sensor is triggered. The time delay is occasionally user-programmable. This is done to save electricity and, in the case of solar sensor lights, to save battery life.

The motion sensor lights are generally set to turn off when 30 to 60 seconds have passed since the movement has halted. Each motion detector light is unique, and each model is configured to stay on for a varied amount of time.

A motion detector light will often remain on for up to 20 minutes. Because that duration is increased each time a sensor detects new movement, a motion detector light can stay on for considerably longer than 20 minutes at any given time.

Because the lights go on and off based on what you set your controls to on the device, how long the lights stay on will vary. When you set up motion sensor lights, you have the option of determining how long every light will be turned on. Adjusting the period each light stays on is a good idea because it could help you save money on your electricity bill.

The location of where you install your motion detector will also play a role in determining how long the light should stay on after being triggered. For example, when you have a motion sensor in a garage or storage room, you’ll usually set the light to immediately go off after a person has left.

However, in your driveway, the light will most likely stay on a little longer because high-traffic areas require longer-lasting lights due to the number of triggers that occur.


What Corrective Actions Should You Take To Fix The Lights?

Motion sensors can be reset to make them as reliable as they once were. Although a professional can be called to help, most of the issues mentioned above can be easily fixed without the help of one.

A quick reset can have your motion sensor up and running again. Before you work on the fixture, ensure that you shut off the power at the circuit breaker panel to avoid electrical shock.


Complete A Quick Troubleshoot

If your motion detector lights are remaining on for too long, the first thing you should do is do a quick troubleshoot. Simply examine the environment around your motion sensor. Check to see if anything has landed in front of your sensor, which could be causing it to stay on continuously.

If a photo-control sensor is present, which is usually near the bottom, wipe it off to remove any debris or dust that could obstruct the sensor.


Move Your Motion Sensor Lights To A Different Area

If you can’t see anything around your sensor, try moving it to a different area for a while. Consider repositioning your motion sensor to a location that does not have heat sources.

If your lights continue to stay on after the sensor has been moved, you will know that the issue was not with the surroundings but rather with the device.


Check The Outputs Of The Motion Sensor

Start by looking at the sensor’s raw measurements to see if they provide any information. Checking the sensor’s output directly can help you figure out if you’re dealing with a hardware problem, such as if your sensor is defective, being falsely triggered by some interference in the environment, or if the hardware has been poorly designed.

The output could also show that the problem may be with the program and needs re-calibration.


Have A Separate Circuit For The Motion Sensor Lights

The trick is to install your motion sensor light on a circuit that does not have items that cause interference. To find out if there is something else on that circuit use a multimeter to see if there are any other items drawing power from the same wire.

If you have a circuit where all of the items plug into one outlet and that outlet has a switch, great! But if your circuit is made up of multiple outlets or wall-mounted fixtures, check with an electrician to make sure you can safely move your lighting to a separate circuit without damaging any of your other devices or appliances.


Change The Settings On Your Motion Sensor Lights

The next thing to do is to change the settings on your sensor. Lights and sensors can be programmed to come on only when anything moves within a particular distance of the sensor.

Look for the sensitivity-adjustable motion-detection switch or dial. If you have a lot of vegetation in your yard like trees, or anything else that could move slightly into the range of the sensor, try lowering the setting.

Ensure that you play around with the sensitivity setting to get the most out of it. Always test the sensor after adjusting the sensitivity settings on your sensor. This is where you can have some fun by placing various objects around the sensor so you can observe how the sensor reacts to various circumstances.

Once you have observed which ones cause your light to turn on, you can choose your desired sensitivity level. Generally, the sensitivity setting is probably too high if the test objects that activate your light are far away or small. Continue to tweak it until it’s just right.

It’s possible that your device is locked in “auto mode” if you recently had a power outage that lasted less than three seconds. Turn off the electricity to the lighting circuit (if the light has its own switch, turn it off as well) and wait at least 10 seconds.

You could also set the ‘on time’ switch or dial to TEST. Change the timer to the shortest numerical option, such as 1 or 5 minutes.


Check Your Manual For Any Adjustments

A manual is always there for a reason. It’s a good idea to examine your manual to double-check your light’s settings. It’s possible that the settings on your light just need to be altered or that your device needs to be reset.


Replace Your Motion Sensor Light

If your motion sensor is powered by AC (such as an outside patio sensor) and controlled by an indoor light switch, double-check that the light switch is operational. Cleaning or replacing these light switches can assist when they start to wear out.

If the above method does not get your lights to switch off, it may be necessary to replace your sensors. Before you go out and buy a new motion sensor, call the customer service number on the manual to see if they have a warranty or any advice for fixing your lights.


Get Professional Assistance

Suppose your device is broken, or you suspect an electrical problem. In that case, you should always seek professional assistance rather than attempting to repair it yourself.

Additionally, if you’ve been trying to fix the problem and yet your lights still won’t switch off and haven’t found a solution, get assistance.



Although motion sensor lights generally perform flawlessly, they too have their moments of ineffectiveness. They are a great safety and security enhancer but can stay on for longer than they should for various reasons.

Now that you are aware of the many things that can cause the motion sensor lights to stay on and how the problem can be fixed, you can have your sensor up and running in no time.

We’ve covered a number of different reasons why your motion sensor light might stay on all the time, and we hope that this article has helped you get your lights working again!

If you liked this article, check out our other articles about motion sensor lights and sensors in general. And as always, feel free to reach out if you have any additional questions. We’re here to help!

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Edward Clark
Edward Clark, with 15 years of hands-on experience, is a distinguished expert in smart locks and home security systems. He holds a B.S. in Computer Engineering with a focus on Cybersecurity and is a member of the Electronic Security Association (ESA). His credentials include certifications from ASIS International, IAPP, CompTIA, NTS, and CEDIA. With expertise spanning risk management, electronic security, and data privacy, he's been featured in The Guardian, Forbes, Wired, and more. Edward's mission: guiding individuals toward secure homes using the latest technologies.

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