How to install a photocell light control

Updated February 21, 2017

Photocell light contols use a photocell to determine when to turn a light on and off. These control units are used on street lights, residential security lights and now automobile lights. Small control units may have two terminals, which are connected to a circuit like a regular switch. Larger control units have three terminals, which are actually two circuits sharing a common hot wire. One circuit houses the photocell, and the other circuit holds the switch that the photocell activates to turn on the lights.

Shut off the power to the circuit or power source that will provide power for the light.

Look at the light control unit and review the manufacturer's installation instructions. Locate the hot wire common terminal on the control unit. This terminal should connect to the black hot wire of the power source.

Connect the white wire of the power source to the white wire of the control unit. Connect the red wire of the control unit to one of the two terminals of the light. Connect the second terminal of the light back to the black hot wire of the power source.

Turn the power source back on and cover the photocell on the light control. The light should turn on in a few seconds. Uncover the photocell and the light should turn off. This test should be done in bright daylight.

Things You'll Need

  • 1 photocell light control
  • Screwdriver
  • Wire cutters
  • Wire strippers
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

William Kinsey lives in Concord, N.C. He started writing articles in March 2009, which have appeared on and He currently holds a Bachelor of Science in electrical engineering from the University of North Carolina at Charlotte and a Master of Business Administration from the University of Phoenix. He also has several years experience as an outside plant engineer and planner with AT&T. He also currently owns and operates Sophisticated Curves, an online fashion mall that caters to the needs of plus size women.