Motion Sensor Light Turns On And Off Repeatedly: Why Does This Happen? [2023 Updated]

motion sensor light turns on and off repeatedly

Motion sensor lights are great safety units emitting incredible illumination. They work using sensor detectors that turn on the light whenever someone is around. 

However, motion sensor lights can end up in a problem. They may start to repeatedly flash off and on or flicker regularly, making the light unusable. This can be annoying as you have spent money on installing these units. But you need not worry as we’ve got a fix for every problem with the motion sensor light. 

In this post, we share with you the reasons that cause flickering and flashing of motion sensor lights and the possible ways to fix them. 

What Are Motion Sensor Lights?

Motion means movement. As indicated clearly by the name, motion sensor lights are electronic safety devices that turn on while detecting a movement. 

These lights are available in different sizes, and shapes, and with varying internal hardware. But the most commonly used are photoelectric sensors that work using infrared radiation. As these lights can easily detect any movement, so they are used to maintain security in commercial and residential regions. 

However, just like other lights, these lights may end in problems. What these problems can be and how you can fix them are explained in this post by our experts. 

So, have a detailed look!

What Are The Different Types Of Motion Sensors?

There are various sizes and shapes of motion sensors available. Each one has a different field range and sensitivity level. Some sensors are meant for external use, while others are suitable for indoor applications.

The different sorts of motion sensors are:

  • Dual Sensor – Such sensors comprise both ultrasonic and infrared technologies.
  • Passive Infrared Sensor – The PIR sensor measures small changes in the infrared radiation and heat for detecting motion.
  • Microwave Sensor – This kind of sensor uses microwave rays for detecting the movement of a moving object in a region. 

Problems With Motion Sensor Lights

A motion sensor light can experience different problems such as:

  • Flickering or Blinking light
  • Regularly Turning on and Off Lights
  • Issues with Sensitivity Settings
  • Light is Turned on Manually
  • Motion Sensor Got Stuck

Every problem occurs because of an underlying reason. Hence, to fix this issue you need to rectify the root cause. 

So, let’s glance at the real causes behind different problems of the motion sensor light.

Why Motion Sensor Light Is Blinking Or Flickering?

The blinking problem is the momentary flash of the light. It occurs when the light is unsteady and releases varying brightness. The flickering problem in light has no relation to the motion sensor. Hence, the possible reasons behind this problem are loose connections, light bulbs, dimming switches, or issues with the light fixture. 

1. Faulty Light Circuit, Fixture Or Bulb

It is one of the common reasons for the flickering problem in the motion sensor light. With usage, the light bulb, fixture, or circuit may get faulty.

Calling an expert for a detailed investigation is a good idea. If there is a problem with the bulb, you may replace the old one with a new bulb. If the problem persists, you need to replace the light fixture. 

A pro electrician can help you fix this problem straight away. 

2. Dimming Switches

Not all motion sensor lights use dimmers. But if your light uses it, then the blinking problem may occur because of a fault in the dimmer switch. The dimmer switches are suitable for incandescent bulbs and do not work with LEDs. 

Also, if the dimmer has become old, it can result in flickering issues. Upgrading the dimmer switch with a new switch can resolve the problem. 

3. Loose Connection And Wiring

Flickering also occurs because of a loose wiring connection. If there is no robust connection between the socket and the light bulb, it can disturb the consistent supply of power from the source. The connection between the socket and the light bulb is the simplest to fix. You just have to tighten the bulb using proper equipment.

Switch off the faulty light and allow the bulb to cool down. Now, remove the existing light bulb and install a new one. Check for loose wirings, bad wall switches, and breakers that trigger the flickering light problem. 

4. Voltage Fluctuations

A drop or spike in voltage can lead to LED light issues. Voltage fluctuation can dim the brightness of light in one go. 

Fluctuations in voltage can occur because of running numerous appliances at once or when a high voltage appliance is turned off. 

Motion Sensor Light Turns On And Off Repeatedly? Why So?

  • Flashing is a short and sudden snap of light that illuminates a particular region. It is often caused by turning on and off the motion sensor light. 
  • The primary reason for flashing in motion sensor light is that it detects the motion interruptedly. This causes the light to switch off and turn on regularly. It is a result of the inadequate configuration of the motion sensor light. 
  • But the good part is that you can solve this problem with a quick fix. You need to adjust the light properly to get things going.
  • Before going for the solution, you must check the maximum delay time and sensitivity settings of the light. This will not solve the problem but will help you determine and rectify other possible issues. 

1. Use The Test Mode

  • Most motion sensor lights come with a test mode. This allows users to adjust the light’s settings after installation. During the test mode, the light turns off quickly after activation. It ensures that the users don’t need to wait longer for the light to switch off before testing other locations and configurations. 
  • To enter the test mode, you need to select the ‘test’ option in the timer settings at the back of the sensor. This is similar to the short time delay of 7-10 seconds. 
  • If your light does not have a test mode, you may choose the minimum time settings for 30 seconds. This will turn off the light fast after activation. 
  • So, check the test mode settings as it can be a reason for the motion sensor light to turn off and on repeatedly. It is important to exit the test mode after testing.

2. Time Delay Setting

The on-time duration controls the duration for which a motion sensor light will stay on once it gets on by a moving thing. When the light switches off quickly, it can be because of the short duration of the on-time setting.

If the time delay setting is too short like 7-10 seconds, it can turn off the light quickly. It is best to select a medium on-time duration setting that can conveniently solve the issue.

3. Sensitivity Setting

The motion sensor light reachability is affected a lot by its sensitivity settings. It detects the motion signal. A too high sensitivity means the motion signals can be captured beyond the detection region or the light may turn on even with a small moving thing.

When the sensitivity is high, the motion sensor detects and sometimes turns on even when there is not much human movement. 

Too low sensitivity of a motion sensor light is not good and fails to detect the existing motion signals within the sensor zone. The motion sensor light may turn off. To reduce the false turning off you must avoid setting the light to low sensitivity. 

4. Position Of The Sensor

The position of the motion sensor light is critical to gaining proper detection results. Check the sensor position right after installing the light. If the adjustment is not up to the mark, it could result in turning off or on the light.

Can I Reset The Motion Detection Sensor To Make It Work Correctly?

  • Most motion sensors get triggered by heat and if you place the light close to a branch or shed, it may not work properly.
  • Also, there are low-quality sensors available that react to simple movements of non-living things or plants. Some such sensors hold a sliding sensitivity scale.
  • This gives the option to trigger a light when a major movement is determined. Make it sensitive so that a small change in the field will spark sensors. 
  • The motion detector can be reset by restoring its factory settings. This helps with developed issues. A few sensors can switch it off, which affects the sensitivity. 
  • There is a standard toggle switch installed with the motion sensor that flips when the light is turned off. The sensitivity changes in different settings. It is because when the sensor is unplugged from the circuit, it connects the power back with a flip.
  • Perform this step a couple of times to gain an adequate level of sensitivity. Finally, check the way your motion sensor works. 

Why I Should Place Motion Sensor Light Away From Heat Sources?

  • The infrared motion sensor light is sensitive to heat changes and thermal signals. It is because the PIR motion detects the infrared signals released from the moving, warm bodies. A temperature difference can activate the PIR motion sensor to switch on the light.
  • If you are using PIR-enabled motion sensor light, you must install it away from a heat source near a window or air conditioner. It is because the hot wind coming out from such devices can damage the motion sensor setting.
  • In case, you cannot place the light away from the heat source, you may turn the position of the motion sensor to a different direction so that it faces away from the heat source. 

How Can I Point The Motion Sensor Light To The Detection Region?

When you reposition or adjust the motion sensor, you must ensure that it properly covers the detection area. The light must be placed in a way so that it is not triggered by the movement of moving cars or animals, which seems like a motion sensor light turning on for no reason.

One noticeable thing is that PIR motion sensor light is better to detect motion across the sensor than toward the sensor. The PIR sensor must not experience difficulty while detecting movement. Hence, the light must be placed adequately. 

How Can I Restrict The Detection Range Of Motion Sensor Light?

It is possible that the motion sensor light does not perform well by simple repositioning. This is not enough to limit the detection range. The light must be placed to bring a large detecting angle of the light ranging from 180 degrees to 360 degrees. 

You may blind the motion sensor lens partially to narrow the detection angle by using adhesive tapes. The tapes work as a blinder covering the motion sensor to prevent the infrared signals from entering from distinct directions. 

How Can I Clean The Sensor Of Motion Light?

It is important to keep the motion sensor clean particularly when you are using it outdoors for security. The light might get covered by spider webs, dirt, and dusks. This can reduce its performance to detect motion. 

Even a medium-size spider can trigger the motion sensor for activating the light when it crawls across the sensor. 

Resetting The Motion Detector Improve The Sensor Light’s Performance?

Motion sensors react to the body’s heat. If people move too close to it, the light may get activated. Resetting is helpful, but not always. 

Using motion sensors is important as it activates the light to offer additional security when a person is away from the building or house. But motion sensors are great for buildings and homes. It is best to combine it with an alarm system.

The light comes with sensitivity and by resetting the motion detector sensor you can gain optimum sensitivity. 

What Should I Do If The Light Is Manually Switched On?

  • A few sensor lights let you manually keep the light on as the manual override feature among switches or as a button in the indoor lights. It is possible that manually the light is turned on.
  • Additionally, there may be a parallel light switch added to the sensor, so the light can be used without using the motion sensor. 
  • Exit or reset the manual mode to see if the motion sensor works back normally. If it does not, you may shut the power completely for a few seconds.
  • If the light is on without the power, it is probably because of a switch that powers the light anywhere else. 

What Happens When The Motion Sensor Is Stuck?

  • The PIR motion sensor light is sensitive and conveniently affected by power blinks and power surges. If there is an increase in voltage, the light can get stuck at the On or Off position and may be unable to function properly. Hence, the light must stay in a proper position for motion detection.
  • If your motion sensor is stuck, you can reset it by shutting off the power for a few minutes for the electronic button to reset. 
  • If there is a reset button that restores the default settings, you may try using it. 

How Can I Fix The Overheating Issue In A Motion Sensor Light?

The overheating of the light fixture can shut down the photosensor. It would take some time to begin the photosensor work again. Hence, you must replace the source of light with a new one. It is best to contact the contractor to look for a sink or an accessory for the lamp holder. 

What All Things Should Be Considered To Buy A Perfect Motion Sensor Light?

There are a variety and quality of motion sensor lights available nowadays. This makes it difficult to select the perfect light. Here are a few aspects you may consider to pick a suitable light:

  • Coverage – Consider the area that the light covers as not all people like too bright light. But other people love bright lights. So, you may pick it up exactly as per your requirement. 
  • Price – It is vital to consider the price of the light that you wish to purchase. It does not mean that you must invest in an expensive one. Pick one that comes within your budget without compromising on performance and quality. 
  • Warranty – It is important if something happens in the guarantee period of the product, you can repair or replace it for free of cost. Hence, always check the warranty information on the product page before you purchase the product. 


Problems with a motion sensor light can occur at any time and are unstoppable, but they can be solved. 

Every problem occurs because of a specific reason. You can either check the issue yourself or contact an expert to get it done for you. 

It is quite cheap to replace the motion sensor light. But make sure you always get a high-quality job done as only then you can procure the desired results. 

If you are facing constant problems with your motion sensor lights, check our solution and fix it immediately. 

Good luck!

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