Never start installing a light sensor or performing other electrical work without shutting off the power first. Use this method when you want to install a light sensor in a finished room that already has a light connected to a switch, such as a bedroom, living room, bathroom, or hallway, for example.
Some light switches might have screws on the backside that hold the wires from the walls in place. If this is the case, use a screwdriver to loosen them until you can detach the wires. Plastic wire nuts are cone-shaped plastic caps that screw onto a set of wires to keep them connected. Your light sensor might come with them or you can buy them separately at a hardware store or online.
The live and neutral wires are always black and white, respectively. The load wire is the wire that connects to the light fixture. It might be a different color than red in your wall, such as black. It usually comes out of the top of the electrical box in the wall, since it is coming down from the ceiling. However, you can only be sure which wire it is if you test all the wires with a multimeter.
The ground wire in your wall will always be bare copper.
You can leave the faceplate off until after you test the light if you want.
Read the light switch sensor’s owner’s manual for any instructions about how to adjust the timing and sensitivity for your specific light sensor. Some models allow you to make the sensor more or less sensitive, adjust how long it keeps the light on, or even change the dimness of the light.
Always do this first before you perform any kind of electrical work. This method is a good option if you want to install a motion sensor light in an unfinished room like a basement or garage. It doesn’t make sense to do it in a finished room where you could more easily install a light switch sensor.
If you have an existing light that you want to connect a light sensor to, like an outdoor light or a light bulb with no switch, you can just swap the whole light for a fixture with a built-in motion sensor. You could install more than 2 junction boxes and wire them all to the box for the motion sensor if you want to connect more than 1 light to the sensor.
Your motion sensor might have different colored wires, such as a brown wire instead of a black wire. If so, refer to the manufacturer’s instructions to be sure which wire is the live wire. Some motion sensors have an easy-to-read wiring diagram on the back that shows you which wires to connect. The neutral wire on the motion sensor can also be blue or green instead of white.
This will make your motion sensor function as the light switch for your LED light.
Depending on the specific model of motion sensor, there might be a mounting bracket that you have to install first or it might just screw directly onto the junction box.
You can use any kind of LED light fixture for this. For example, if you are installing a motion sensor light somewhere like a basement with low clearance, you could use a low-profile, flush-mount LED light.
If you used an adjustable light fixture of some type, you can now adjust it so the light hits exactly where you want it to.
