Why Is Motion Sensor Light Blinking? 5 Steps of Resetting Motion Sensor Lights

Why Is Motion Sensor Light Blinking?
Image of a Motion Sensor

The other day, a reader asked this question: “Why is my motion sensor light blinking? I decided to write an article on this subject to help others who might have noticed the same thing with their motion sensors. So keep reading for more…

Motion sensors are electronic devices designed to detect or measure movement. They are excellent security essentials that protect your home or business premises from burglary, wild animals, Prowlers, and any other suspicious movements.

A perfectly functional motion sensor should give you optimum protection and superior mental peace. However, it becomes frustrating when the sensors turn on and off, regardless of whether or not it has detected a movement.

If your light is “blinking,” it displays a momentary flash that’s unsteady and with varying brightness. The problem is usually linked to the light fixture, bulbs, and loose connection. Usually, a blinking or flickering motion sensor does not indicate a problem with the sensor. 

Why Is Motion Sensor Light Blinking?

Based on our experience and several research pieces, the following are the possible reasons why your motion sensor light is blinking:

Loose Wiring and Connection

One of the common causes of a flickering light is a loose light bulb. A loose connection often means poor contact between the bulb and the socket. It will result in an inconsistent power supply from the source to the bulb, manifesting in the “blinking.”

The good news is that this is also the most manageable problem to fix. All you need to do is to tighten or fasten the light bulb. 

Before first, consider turning the power off and wait for the bulb to cool its heat off. Gloves protect your hand from heat, so wear them and tighten the light bulb.

Also, you won’t appreciate loose Wiring in your house as it will trigger other lights to flicker. It also will lead to a possible life-threatening situation as it is considered one of the primary causes of the fire that should never be overlooked. 

While you can fix this problem yourself, hiring an electrician is equally wise as they will solve the problem and thoroughly examine your house.

Faulty Bulb, Fixture, or Circuit

When you see a flickering light, the first thing that pops into your mind is that “something is wrong somewhere.” You might be right! Like any other device or application, the light bulb, fixture, and electric circuit may malfunction after use for an extended period.

We will unlikely give you a straightforward answer on what causes the blink. However, replacing the bulb could quickly fix it. 

However, if the problem persists, it would help to replace the whole light fixture with any working light fixture. If this doesn’t solve the issue, please call a licensed electrician to examine the circuit for possible causes. 

Voltage Fluctuations

An inconsistent flow of electric currents will result in a flickering LED light. If the voltage fluctuates (increases or drops), the LED light would, in turn, be bright or dim. 

It explains how the LED light mechanism functions. They don’t use a filament for illumination. Instead, it is the electronic driver that produces lighting. As such, the fluctuations in the voltage will reflect in the brightness output of the LED lights.

Also, incandescent light bulbs heat the filament to produce light; this is how it illuminates. Therefore, fluctuations in the voltage will not instantly cause the light to flicker for incandescent bulbs.

Additionally, if you are simultaneously using your appliances, the LED lights are bound to flicker each time you turn the appliances on and off, contributing to voltage fluctuations.

If you suspect that the voltage changes are responsible for your motion sensor’s blinking, it will help if you replace it with another non-LEF light bulb. While this is not optimal, it will still solve the issue.

Using Dimmer Switches

Under normal circumstances, dimmer switches are never compatible with motion sensor lights. However, using them is perfectly compatible with incandescent bulbs rather than LED lights. 

Like any other appliance, continuous use of the dimmer switch will cause wear and tear. An old dimmer switch can contribute to your motion sensor’s light flickering.

Typically, we don’t use dimmer switches along with motion sensor lights. But if you do, old dimmer switches are designed for incandescent bulbs and do not work well with LED lights, which might cause flickering.

If your dimmer switch is aged, it might be why your light is flickering. 

You can upgrade your dimmer switches with a new one and solve the flickering problem. New dimmer switches should work well with LED lights.

Test Mode

Almost all motion sensor brands have test mode features allowing users to configure the settings after installing. Expect your light to turn off quickly after activating the test mode.

Therefore, you won’t need to wait an extended period for these lights to go off before testing other settings and locations. For this reason, we advise entering the test mode before configuring other settings.

To use the test mode, select the “test” or “test mode” feature in your timer’s settings, often located at the back of your sensor.

This test mode functions similarly to the “delay feature,” but this is a remarkably brief delay of about five to ten seconds, exclusively meant for testing purposes.

NOTE: Not all motion sensors, especially those designed for indoor use, feature the test mode setting. If this is your device, please select the minimum timer setting of 30 seconds. It will let your light turn off as soon as you activate it. 

Interestingly, the test mode feature could also be a reason behind your motion sensor’s blinking. The short time setting will cause it to blink constantly, especially if the user forgets to exit the test mode after finishing testing.

On-Time Duration

As we’ve mentioned earlier, you can configure the settings in your motion sensor device to suit your individual preferences. The settings changes often include the on-time or time delay, which controls the period the sensor stays on once it detects motion. 

If you notice the sensor turning off sooner than you’d appreciate, the short-time setting could be the reason.

A short delay of about ten seconds on your motion sensor lights means that the lights will quickly turn off when they fail to pick a motion after ten seconds. Therefore, the idea that a short on-time duration will cause your motion sensor lights to blink is a no-brainer! 

Consider resetting your motion sensor to a medium time setting of about ten minutes; the problem should be solved in a blink.

Sensitivity Setting

Your motion sensor lights could also be blinking because of the sensitivity settings. 

A high sensitivity Setting equals your device constantly being triggered, even in the slightest motion. Sometimes, the sensor can become so sensitive that it detects non-human movement and gets triggered. 

Consider adjusting the sensitivity settings if your device is frequently going on and off or blinking. Adjust it to a lower level to minimize the number of false alarms.

Conversely, adjusting to a “low sensitivity” level could be a bummer! Such a setting will leave you exposed and vulnerable to dangerous situations because a “too low” sensitivity level minimizes your sensor’s ability to detect suspicious movements in the sensor zone. 

As a result, your sensor might turn off as it speculates that the “targeted area” is empty despite people’s presence. 

If your sensor lights frequently turn off, please adjust the settings to high sensitivity to reduce the false-offs. 

In other words, it helps to adjust your sensitivity settings moderately. Too high or too low sensitivity levels significantly contribute to your motion sensor lights blinking.

Sensor’s Position/ Location

The location of your sensor is crucial as it determines how precise or faulty your sensor will function. However, it is a concept many home/business owners tend to ignore. 

Installing your motion sensor in the wrong location will result in it turning on too often or off too soon.

For instance, motion sensors that use the PIR technology are usually susceptible to thermal signals and heat changes. Any temperature change would trigger the PIR sensor.

PIR motion sensor lights are sensitive to thermal signals and heat changes because PIR motion sensors detect the infrared signals emitted from warm, moving bodies. 

Almost everything, including inanimate objects like walls, doors, and cars, will emit this infrared energy detected by the PIR.

Any temperature difference may trigger a PIR motion sensor to turn on the light.

Installing your sensor near heat sources such as the air conditioner or windows that receive hot wind could produce frequent false alarms. These false alarms are, in turn, manifested through blinking. 

With this knowledge of PIR motion sensor technology, is it surprising that heat sources could easily trigger the PIR sensor?

Poorly aiming your motion sensor also contributes to frequent blinking. If you wrongly aim your sensor, expect it to get triggered by any object in motion, including wild animals and cars. 

It will cause false alarms and, in turn, cause blinking. For this reason, we encourage you always to follow the holder rule of ensuring your sensor only covers your “target area.”

Presence of Dirt and Debris on Your Motion Sensor

Your outdoor motion sensor lights will likely accumulate dirt and debris, a problem most home/business premise owners ignore.

When dust and dirt cover the motion sensor, it reduces its ability to detect motion, contributing to blinking. 

We’ve seen that various ideas exist on why your motion sensor lights could be blinking. One of the addressed concerns that cause this is the settings. Let’s now expand on this! 

What Are the 3 Settings on a Motion Sensor Light?

Most motion sensor lights have three primary settings: sensitivity, timer, and lux. These settings are crucial as they determine your device’s sensitivity to movement, the period length your light will stay on once it dictates the movement, and the darkness level that will turn it on. 

Let’s discuss them more.


The sensitivity setting determines how sensitive your motion sensor is. Because of this, it also influences how effectively your device detects movement in the targeted area. 

Furthermore, the higher the sensitivity setting, the more sensitive the device is to motion. With this setting, your motion sensor light will turn on often, sometimes too often, because slight or unnecessary movement will also trigger the alarm.

 The high sensitivity setting increases the likelihood of false triggers from your alarm.

The sensor becomes less sensitive to movement when the sensitivity setting is low. As such, your motion light will not turn on as quickly but only when it detects a human presence. 


A motion sensor is designed to turn on upon detecting a movement. This is where the timer setting is connected. It determines the period the light will stay on once it detects motion. 

A higher timer setting means the light will stay on longer, an important feature, particularly if you’d want your lights to stay on longer after a person leaves a given environment. 

While this is good, it could also hurt your pockets as it’ll increase your electricity bill because it can cause the light to stay on all night for as long as someone moves around in the area. 

A lower timer setting equals a shorter “lights on” period. It will help if you prefer the light to stay on only briefly after the device detects movement. This setting will help you conserve energy while also reducing your electricity bill. 


The lux setting influences the level of darkness that will turn your motion sensor on. Put a higher lux setting if you want your lights to go on in complete darkness, a cost-effective and energy-saving setting, as the light will only go on in extremely dark conditions.

On the flip side, this setting may result in the light not turning on despite having a meager amount of light present. 

If you adjust to a lower lux setting, your motion sensor will turn on even in darker situations, which will help if you want your lights on in darker conditions.

Takeaway: The sensitivity, timer, and lux settings on your motion sensor determine how sensitive your device is to move, how long the light will stay on upon detecting motion, and the level of darkness that will turn the light on. You can adjust these settings to suit your unique security needs and preferences. 

Besides the settings, we’ve also learned about possible reasons why your motion sensor is blinking. It means that your device blinking is not a cause for alarm, as it is a solvable situation. Let’s now learn how to stop the blinking.

How Do I Stop My Sensor Light from Blinking?

One of the most common causes of your motion sensor blinking is a faulty Bulb. Before considering any other solution, you want to ensure that your bulb is in good condition. 

Therefore, replace/ change the bulb. If the problem persists, don’t hesitate to contact an electrician to examine your circuit, as there could be more significant problems. 

Below are other troubleshooting tips you should consider if your motion sensor lights keep blinking:

Adjust the Sensor Settings

One of the reasons why your motion sensor won’t stop blinking is the sensor settings. Most brands have an adjustable sensor that trips anytime it detects a change in heat.

If you’ve not correctly adjusted the sensor, your device can pick up heat from unnecessary zones, for instance, when a branch moves or a passing car passes. The following steps will help you adjust the sensor settings:

1. Move your sensor from “operational” to “test mode.”

Locate this switch at the bottom of your sensor. It will turn the lights off after a few seconds. It will allow you to test the different settings quickly.

2. Correctly Aim Your Sensor in Your Preferred “Targeted Vicinity.”

Properly adjust your sensor to point only to the area you want to be guarded. For instance, ensure the sensor is tilted down far enough if you want it to detect movement within the driveway. 

This way, your sensor won’t catch movement from the street but will be high enough not to get triggered by the flowers lining the driveway.

3. Find the “Range Dial” at the Bottom of Your Sensor

This feature will help you determine the distance you want your sensor to pick up heat or movement. 

If you notice it’s set to the “max” range, please adjust it to a lower range. The “max” range contributes to false triggers as your device will unnecessarily pick movement or heat from objects. The lower range will ensure that only movement within the targeted vicinity is detected.

4. Adjust Any Pet Immunity Sensors

Some motion detector brands contain features from which you can choose a pet immunity setting. Ensure you activate this setting if you have pets or neighbors moving around. It’s meant to prevent false triggers from pets of a given weight. 

Next, these pet immunity settings give you a weight option. Ensure you set your sensors to a weight that matches the animals that can frequently pass by your sensor’s target area.

5. Finally, Reset Your Sensor from the “Test Mode” to the “Operational Mode.”

If your efforts to change all these settings prove futile, and your motion sensor lights are still blinking unnecessarily, continue with the following tips.

Try “Side Blinders”

All motion sensor lights contain a given angle range. Most of them range between 180 to 360 degrees. However, these angle ranges are often too wide, allowing unnecessary movements like tree branches swaying to trigger the sensor. In such a case, your sensor will likely experience frequent blinking. 

Solve this by putting thin electrical tape on one or both sides of your sensor. It will help in narrowing or limiting its visual field. Adjust your sensor to the test mode before doing this, as it is a “trial and error” process until you find an angle you prefer. 

If you’ve attempted the suggested troubleshooting tips, but the sensor won’t stop blinking, it could indicate a more significant electrical problem. At this point, it will help to hire an electrician to investigate the source of the problem. 

How Do You Reset a Motion Sensor Light?

You’ll need to reset your motion sensor light for various reasons; it may be stuck in the on or off position or affected by fluctuations in the power supply. 

While you may assume your fixture is broken, you’d be surprised that a reset could solve all your problems!

Resetting doesn’t require any special tools or skills! It will save you the hassle and money you could have thrown down the drain!

Before we learn how to reset the sensor, let’s first understand situations requiring you to reset it. The following are examples of such situations:

  • Reset when your sensor lights are not triggered by movement from large objects like humans or vehicles. 
  • Suppose your sensor lights stay on permanently or for a prolonged period. A perfectly functional sensor will turn on once it detects movement but turn off as soon as it stops.
  • If you also notice that your sensor is less sensitive than usual and does not consistently detect motion.

If your problem resembles any of the suggested instances, try troubleshooting your motion sensor, as it will help solve the problem.

Described below is how you reset your motion sensor lights:

  • Locate the fixture’s circuit breaker and turn it off for about 30 seconds. 
  • If your fixture contains a light switch, turn it on for about two seconds, then off for another 2 seconds. Turn it back on again. 
  • Once the light is on, turn the switch off for about five seconds and switch it back on. 
  • Most devices contain the settings adjustment feature. Locate it and readjust the sensitivity level to a less sensitive level. Besides, it would frustrate you if even the slightest movement triggered your motion sensor. While you don’t want this to happen, you don’t want to leave yourself susceptible to insecurity. Ensure the sensor is sensitive enough to identify a trespasser on your property.
  • Also, you want to ensure that the bulb is not an issue, so replace it in the light fixture as you troubleshoot other possible malfunctions.

Here’s a Video On How to Reset Motion Sensor Light:


How Do You Clean the Sensor On a Motion Sensor Light?

Dust, dirt, and debris are environmental elements that can accumulate on your motion sensor. 

Please don’t let it get to this level, as you can clean the sensor, and your device will be as good as new! It will, in turn, interfere with its sensitivity by dimming the bulb’s capacity to light up appropriately, thus leaving you uncovered against insecurity. 

Clean the sensor using a soft and moistened cloth. Moisten this cloth piece with a cleaning solution such as a window cleaner. Use it to remove the dust and mildew accumulated on the sensor. 

You can also find insects and spider webs from the fixture and bulb; ensure you get rid of them, too. 

While cleaning, please pay special attention to the infrared sensor’s lens, which triggers the light once it detects motion.

What Are the Signs That the Sensors Are Failing?

Motion sensors are excellent security essentials that will alert you if you are insecure or life-threatening. They are also cost-effective for light walkways, driveways, and other target areas requiring extra home security or work security. 

However, these devices are inevitably exposed to external elements like weather, sunshine, dirt, and grime that can destroy them. If the malfunction happens, the target areas are exposed with no security, posing a severe problem. 

The good news is that we have learned, and you already know how to troubleshoot, should you suspect your sensor is failing. 

It would help understand the warning indicators the sensors are failing even further. Which will help identify the problem and restore the service on time!

While there are several warning signs of a failing motion sensor, the most apparent is when the lights don’t turn on. You’ll notice that the sensor does not detect motion even when large objects are around its vision field. 

Also, your light staying on permanently is a red flag that the device is malfunctioning. A standard sensor is designed to turn on once it detects motion or heat and then turns off after an estimated period. 

Final Thoughts

Motion sensors are security necessities that guard our lives and properties against harm. Therefore, we expect them always to be accurate and perfectly functional. 

It should worry you if you notice any signs indicating a malfunction. In regards to this, this article has answered the question, “Why is the motion sensor light blinking?”

There are several reasons why the sensor blinks: a faulty bulb, a loose electrical connection, wrong sensor position, sensitivity settings, etc.

Identifying the possible cause of your sensor’s problem will help you develop the necessary solution. Next time you notice it blinking, don’t panic! The solution could be a setting adjustment away.

We wish you good luck as you attempt to resolve any issues with your motion sensor lights.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.