Outdoor Motion Sensor Light Blinking Red: Why and How to Fix?

Outdoor motion sensor lights are certainly convenient for providing security and illumination around your home. However, when the light begins blinking red erratically, it quickly becomes a nuisance. This blinking indicates a problem with the sensor that requires some troubleshooting and maintenance to correct.

Nine times out of ten, a simple reset can fix the blinking red light issue on your motion sensor. There are some other fixes as well, which I have described below.

What Causes Motion Lights to Blink Red?

There are a variety of reasons why your motion light may have a blinking red indicator. Here are some of the most common causes to be aware of:

Low Battery Power

Many motion sensor lights will blink red when the battery power is getting low. The average AA alkaline batteries only last about 6 months in a motion sensor light. Installing a high quality lithium battery can extend the life to over 1 year before needing replacement. Get in the habit of replacing your batteries regularly to prevent premature low battery blinking.

Faulty Motion Sensor

If the motion sensor itself is defective, it can cause false activations and make the light blink red even when no motion is detected. This could be due to age and wear, weather damage, insects blocking the sensor, or simple malfunction. Carefully cleaning the sensor lens and repositioning the light can sometimes help, but a sensor replacement may be required if the issue persists.

Excessive Motion Triggers

When the motion sensor light is located in an area prone to frequent activation, such as near trees and branches that sway in the wind, this can lead to excessive blinking. Small animals and flying insects can also continually trigger the sensor. Adjusting the motion sensitivity settings lower, repositioning the light away from environmental triggers, and installing external light-blocking shields can help mitigate false alarms.

Incorrect Dusk-to-Dawn Setting

Many motion lights have a dusk-to-dawn setting that automatically turns the light on at night and off during the day. If this setting is enabled when not needed, it can cause the sensor to become confused and blink red erratically at night when it can’t determine daylight conditions. Disabling this setting solves the problem.

Adverse Weather Conditions

Extreme cold, heat, and humidity levels can sometimes interfere with the motion sensor and cause intermittent blinking when no motion is present. Using a light designed specifically for the climate and protecting it from weather extremes prevents malfunction.

Daylight Saving Time Disruption

Oddly enough, the transition to and from Daylight Saving Time can temporarily disrupt a motion sensor light’s settings. The hour time change seems to confuse some sensors. Often, this can be fixed by simply turning the light’s power off and back on to reset it.

LED Bulb Issues

If the motion sensor light uses LED bulbs, installing the wrong bulb type or wattage can cause issues. Faulty wiring connections between the bulbs and sensor can also lead to blinking. Always check the bulb specifications and wiring to ensure proper setup.

Age and General Wear

Motion sensors used for many years may simply begin to wear out and malfunction, exhibiting blinking or odd behavior. If your light sensor is outdated or failing, replacing the entire unit will be the solution.

How to Permanently Fix a Blinking Motion Light?

To stop the nuisance of a constantly blinking motion sensor light, here are some tips:

1. Begin by replacing old batteries with fresh ones. Lithium batteries are best for long life.
2. Thoroughly clean the motion sensor lens with a soft cloth and check for any dirt or insect obstructions.
3. Adjust the sensitivity settings to avoid activations from small animals and wind-blown debris. Too high of sensitivity causes false alarms.
4. If your light has an automated dusk-to-dawn setting enabled, disable this if you only want motion activation.
5. Reposition the light away from trees and objects that may be triggering the sensor inadvertently.
6. Do a complete power reset by turning the light switch or breaker off for 1 minute, then back on. This resets the sensor.
7. Ensure your light bulb type and watts match the recommended specifications. Check that all wiring connections are intact.
8. If blinking persists despite troubleshooting, replace the motion sensor with a new unit of the same type.
9. Install external light blocking shields properly adjusted to the sensor’s field of view to prevent false activations.
10. Locate a small reset button on the light fixture to reset its settings to factory default if needed.

Why does my outdoor motion light stay on all night long?

If your motion light remains on continuously at night, this typically indicates the motion sensor is defective and stuck in the “on” position, or the manual mode is accidentally activated. Check any manual switches on the light fixture and turn off manual override mode in the settings if enabled. If the light remains on constantly without motion, the sensor likely needs to be replaced.

How can I stop small insects and animals from making my motion light blink all night long?

To prevent tiny flying insects and small wildlife from triggering your motion sensor constantly, you can install an insect screen to block bugs, position the light higher up aimed downward, adjust the sensitivity lower, and add external light shields. This will limit the sensor coverage area and block nuisance activations.