Things You'll Need
Touch-type voltage tester
Motion lights are great additions to the outside of your home because they not only come on automatically when someone gets within range of the sensor, but if there's no activity, they remain off. This improves your home's security while preventing the lights from unnecessarily staying on all night and running up your electric bill. Plus, if you have more than one outside light on the same circuit, you can control them all with a single motion sensor. All it takes is a slight change in the wiring, which most people can do themselves.
Turn off the power to the outside lighting circuit. To prevent accidental injury from electric shock, turn the power off at the breaker, not the light switch.
Remove the light bulbs from the fixture where you are going to install the motion sensor.
Disassemble the fixture with a screwdriver so you can access the wiring. Before you touch any wires, use the touch-type voltage tester to make sure that the circuit is off. Press the test button on the tester and touch the tip of the tester to the black feed wire in the junction box. If the tester doesn't beep or light up, the circuit is off.
Disconnect the wire connections that link the fixture wires to the wires coming out of the wall. The wires that lead to the next fixture in the series will also be included in these connections.
Remove a knockout on the wall box where you will be installing the motion sensor. The knockout can either be removed by unscrewing it or tapping it out with a hammer and screwdriver.
Slide the rubber washer over the wires and threaded nipple on the motion sensor. The rubber washer comes packaged with the sensor and in some cases is already on the sensor when you remove it from the package.
Insert the motion sensor's wires through the knockout hole and screw the sensor down tight. If the knockout doesn't have pre-existing threads, secure the sensor to the wall box with the lock nut that comes with it.
Remove about 3/4 inch of insulation (if necessary) from the ends of the wires in the box, using wire strippers, so you can make good connections. Look at the wires and familiarize yourself with them. There should be a black, white and ground wire coming out of the wall (these are your feed wires); a black, white and ground wire that leads to the next fixture; and a black, red and white wire coming from the motion sensor. Also, the fixture has its own set of black, white and ground wires.
Connect the black wall wire it to the black wire coming from the motion sensor. Secure it tightly with a wire connector and wrap electrical tape around the connection.
Connect the white wall wire with the white wire coming from the motion sensor, the white wire leading to the next fixture and the white wire on the present light fixture. Secure the wires tightly with a wire connector and wrap electrical tape around the connection.
Connect all of the ground wires together in the same manner. Secure the wires tightly with a wire connector and wrap electrical tape around the connection.
Connect the red wire from the motion sensor with the black wire from the present fixture and the black wire leading to the next fixture. Secure the wires tightly with a wire connector and wrap electrical tape around the connection.
Stuff the wire connections carefully back into the wall box and re-secure the outside light fixture to the box.
Install the light bulbs and turn the circuit back on. If the light switch is currently off, turn it on and leave it on. The fixtures should all turn on for a few seconds and then automatically turn off. Once it becomes darker outside, adjust the sensitivity and range on the motion sensor so it works the way you want it to.
Don't work on a live circuit. Always turn it off at the breaker to avoid accidental shock. If you're working on a ladder, always have someone working with you to watch the ladder.