How To Troubleshoot Motion Sensor Light Issues

Posted on: 20 September 2017


Motion sensor lights alert you to movement in your yard by beeping and flashing, and they allow you to see your way around the house at night. However, you may experience a light that won't come on and other issues. 

You don't always have to take the unit for a professional repair. Many times, the issue is simple to fix. Troubleshoot and fix motion sensor light tissues by following these tips:

Diagnose  Motion Lights That Won't Come On

Gather a voltmeter a screwdriver, pliers, a clean cloth, and replacement bulbs. Check the reset button on the bottom of the sensor, which may have frozen in colder weather or rain. Press it, and hold it several seconds each time.

 Use the screwdriver to loosen the screws on the service panel, and look for the breaker that controls the light. A tripped breaker moves to the middle or opposite the other breakers.

Shut off the breaker that controls the sensor, and inspect the bulbs. Corrosion or cloudiness means the bulb needs replacing. Unscrew the old bulb, install a new one, then press reset to test.

Inspect the photocell for dirt and debris, which could interfere with range. Use a damp rag to clean it, and try the light again., 

Fix Motion Lights That Stay On

Again, the weather could be the culprit. If this happens in cold weather, unscrew the bulbs, and set them in a warm spot for several minutes. Keep the sensor pointed away from heating units and heat vents that may raise the temperature to trigger rights to stay on constantly.  

Position the sensor light away from trees and shrubs since the movement of leaves and trees in the wind could cause the sensor to remain on. 

Check the 'test' button to make certain it isn't pressed. The 'test' button function may likewise cause the light to stay on. The light switch setting should be in 'automatic' mode. If the light continues to malfunction, it means the photocell is faulty and whole unit needs replacing. Proceed with the voltmeter test to be certain.

Test with a Voltmeter

Turn off the power to the light, disconnect the fixture, and access the wires. Use the 120v setting to test the sensor when nothing else seems to work. Attach one voltmeter contact on the positive black wire of the sensor, and connect the other probe to the white wire. 

You should get a reading between 108v and 120v. A reading of 0 (infinity) indicates a dead unit. Get an electrician to check out the house wiring if you get a reading above 120v.