How to Troubleshoot a Security Light Malfunction

Check the power source. Verify both that the light is getting power and that the power source is not being turned off with a light switch. Make sure all the breakers and light switches going to the light are on and in working order and that no wires are disconnected.

Tighten the bulbs in the light if they feel loose. Changing the bulbs may solve the problem completely. If one or more of the bulbs appears to have a darkened film forming on the inside of the glass, the bulb is likely burned out and will not operate anymore.

Wipe down the light with a clean rag to remove any loose dust and debris. Pay particular attention to the light's sensors. If the sensor is dirty, the light could turn off and on intermittently or stop working entirely.

Re-aim the light to make sure it is placed properly. Have someone stand nearby if the light uses motion sensors so you can adjust the height of the light while your helper walks by to see if the light detects the movement. If the device is light-sensitive, adjust the sensitivity by either adjusting a switch on the light or by turning a screw, depending on the light model. If the light is not sensitive enough, it won't turn on, while an overly sensitive light may flicker.