How to Install a Motion Detector on a Light

Installing a motion detector is an inexpensive way to increase your outdoor security. Most motion detectors are paired with light fixtures for easy installation and are available in a wide variety of wattages and sizes. The most common fixture sold is a two-bulb, 120-watt motion detector system. This type of motion detector is often mounted on a garage or near a side entrance. Ornamental, single bulb motion detector light fixtures have also been developed for residential use and are appropriate to install on front facades.

Things You'll Need

• Screwdriver
• Circuit tester
• Outdoor caulk
• Wire nuts
• Motion detector light fixture kit

Instructions

1. Turn off the power to the existing light from the breaker box. Make sure that the light is off by flipping the switch.

2. Remove the screws that hold the old fixture in place. The light fixture will still be attached to the wall, so be sure to support it with one hand. Sometimes the fixture will twist off of an independent base. If you have this type of fixture, remove the screws that hold the base to the wall.

3. Using a circuit tester, make sure that the wires are not live. Most circuit testers work by attaching one end of the tester to one of two exposed wires and then touching the other end of the tester to the other exposed wire. If the circuit tester does not light up, it is safe to proceed. If it does light up, verify that the circuit breaker has disconnected the electricity to the fixture and test again.

4. Detach the light fixture wires from the electrical service wires in the wall. In most cases they will be attached with wire nuts, which simply twist off and then allow the wires to be untangled. Older homes may have the wires attached with electrical tape. To detach, simply remove the electrical tape and twist the wires apart.

5. Fill in any screw holes with outdoor caulk. This will help maintain the integrity of the exterior shell of your home. You may also want to touch up the exterior paint if the new fixture does not cover all imperfections.

6. Attach the independent fixture base to the exterior wall, drilling pilot holes and using the screws provided. Skip this step if your motion detector does not have an independent fixture base.

7. Connect the wires from the motion detector to the electrical service wires in the exterior wall. Be sure to match the white and black colored wires and use wire nuts to secure the connection. Tuck the wires into the wall cavity.

8. Slide the motion detector onto the independent fixture base. If you have a baseless motion detector, drill pilot holes and attach the fixture to the wall using the screws provided.

9. Screw in the light bulb and restore electricity to the circuit by flipping the switch at the circuit breaker. Test the motion detector by waving your hand near the sensor after dark to verify that it turns on.

Tips & Warnings

• Twist the ends of the electrical service wires around a pencil when they are not attached to a fixture. This will prevent them from falling into the wall.

• Never install a motion detector without turning off the electricity to the circuit and verifying that you were successful.