How to Fix a Dusk to Dawn Light Fixture

By Dave Rongey - Summary:

How to Repair a Dusk to Dawn or Motion Detector Light Fixture: Security Light Fixture TEST Setting Functions, Replacing a Motion Detector Head on a Dusk to Dawn Fixture, How to Test a Photo Cell.

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What To Do If  Your Dusk To Dawn Fixture is Erratic

Electrical Question: My dusk to dawn light has become erratic, coming on at dusk, staying on a while, going out, coming back on for a few minutes, going out, coming on for a while, going out.

  • The security light fixture has worked perfectly for several years.
  • Should I change the light bulb, sensor or the whole light?


This electrical wiring question came from: Rick who is a Handyman from California.

Dave’s Reply:
Thanks for your electrical question Rick.

How to Repair a Dusk to Dawn or Motion Detector Light Fixture

Application: Repair a Dusk to Dawn Light Fixture.
Skill Level: Beginner to Intermediate.
Tools Required: Basic Hand Tools and Safe Ladder.
Estimated Time: Depends on personal experience, the light fixture and access to the light fixture.
Precaution: Identify the light fixture circuit, turn it OFF and Tag it with a Note before working with the wiring.
Notice: Replacement parts for the security light fixture should be compatible with the type of fixture that has been installed.

Security Light Fixture TEST Setting Functions

  • Rick, first of all make sure that the motion detector head is not switched into the TEST setting.
  • The TEST setting will over-ride the photo cell and will cause the fixture to trigger the lights to come on when any movement is sensed at any time.

Replacing a Motion Detector Head on a Dusk to Dawn Fixture

  • If necessary the motion detector head may be purchased to replace the defective motion detector head.
  • You will notice that there are a variety of sensing capabilities available, and the more sensitive the head the higher the price.
  • You may also want to compare the price of the motion detector head all by itself compared to a whole new light fixture.
  • Replacing the motion detector head typically involves the following three wires:
    • Black wire for the incoming power.
    • Red wire for the outgoing power to the light bulb sockets.
    • White neutral wire, which is typically spliced together with the white wires of the incoming power source neutral, and the white wires to each light socket.

How to Test a Photo Cell

  • If the outdoor light fixture does not have a standard motion detector head with a TEST switch option, and you need to test the photo cell, then follow the example in the following process:
    • Locate the photo cell on the light fixture, or the external photo cell control.
    • Typically the actual photo cell is inside the unit behind a round clear plastic lens, which may be located on the bottom of the motion detector, or the front side.
    • With the power on to the light fixture, place a small strip of black electrical tape over the photo cell to block the light.
    • Depending on the photo cell it may take about 30 seconds for the photo cell to turn on.
    • If the photo cell and control circuitry is functioning properly, and the light bulbs are good the fixture should light up.
    • After testing the photo cell be sure to remove the black electrical tape which will place it back into the automatic mode of operation.

More about Wiring Motion Detectors and Dusk to Dawn Light Fixtures

Dusk to Dawn Lighting and Motion Detector Wiring

  • Installing Motion Detector and Security Light Fixtures

  • Installing motion detector lighting fixtures provide security and energy savings and they can easily replace an existing exterior wall fixture.

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FAQs Frequently Asked Questions and Comments

16 Responses to “How to Fix a Dusk to Dawn Light Fixture”
  1. Susan Davis says:

    I have a dust to dawn light that quit working. I replaced the light bulb twice and the sensor on top has power coming into all the areas but the light still will not work. Is there anything else I should replace?

    • Dave Rongey says:

      Hi Susan,
      Make sure you are testing the dusk to dawn light fixture with the switches in the “TEST” position if you are working with the fixture in the day time. This will over ride the photocell and allow you to test the motion sensor directly. Typically the black wire of the motion detector head is connected to the incoming circuit power which is usually black, and the red wire of the motion detector is connected to the wires leading to the lamp holders, and then the white wires are all spliced together. Sometimes the motion detector head can go bad and quit working, especially if moisture gets inside the unit. In that case the motion detector head will need to be replaced with a new one, which is available from most hardware stores.
      Make sure the circuit power is off before checking any wiring connections.
      I hope this sheds some light on this,

  2. judy atwell says:

    Our light goes out when we open our garage door.

    • Dave Rongey says:

      Hi Judy,
      More information would be helpful, however you may start by having the wiring to the light examined to make sure it has been installed properly.

      I hope this helps,

  3. Joyce Hamilton says:

    I have a dust-to-dawn light that is working improperly. We replaced the eye about 3 months ago and the light would come on for a few seconds and shut off. Today, we replaced the bulb and now it does not come on at all. What do we need to do next?

    • Dave Rongey says:

      Hi Joyce,
      Check the settings on the eye to make sure they are correct. Make sure the lamps are compatible with the light fixture, and just in case, make sure there is not a switch in the home that controls the light fixture that is getting turned off.
      I hope this helps you Joyce,

      • Joyce Hamilton says:

        Thanks, Dave we will try what you suggest. The dusk-to-dawn light is on front of the garage and on a separate fuse box.

  4. peter.parrish says:

    I have a dusk to dawn half lantern with high low sensor that is now broken down and I can’t find one like it anywhere. Ive been searching on internet three days, any ideas? Thanks Peter

    • Dave Rongey says:

      Hi Peter,
      Try searching for the fixture at home depot, Lowes, pottery barn, or any other light fixture supplier.
      An image search for Lantern Light Fixture using any search service may be very helpful as well. If you locate the light fixture and does not have the dusk to dawn control you might be able to adapt the control to the fixture, or install a dusk to dawn control into a separate fixture box.
      I hope this helps,

  5. Buddy says:

    Hi, my dusk to dawn lights are staying on all the time. There are four all on same photo cell. I replaced the photo cell and still the same thing. I replaced the receptacle that the photocell plugs in to as well and I still have the same problem. I know the wiring is correct because they have worked for years up to this. Any suggestions as to what this might be?

    • Dave Rongey says:

      Hi Buddy,
      From what you have described it sounds like you have a separate photocell that controls the power to the dusk to dawn light fixture. In any case, it may be helpful to know that most motion detector controlled light fixtures or dusk to dawn light fixtures typically operate with a continuous power supply. Many of these light fixtures have the ability to manually toggle into a Manual On or into the Automatic mode when the power supply has been toggled on and off. This could also occur when a photo cell has been installed ahead of the dusk to dawn light fixture. Therefore, it would be best to control a standard light fixture with a photocell, or have a dusk to dawn light fixture with the typical motion control module that has a constant power source.
      I hope this helps, let us know what works best for your application,

  6. Suzy says:

    I have dusk to dawn sensors in the lamps outside of my garage. The lamp has 3 lights. Each light has a dusk to dawn sensor screwed into the socket, but only one light will burn at a time. When one burns out, it has to be replaced before the light will work. I don’t understand first of all why all three do not burn at the same time and secondly, why don’t the other one start coming on if one burns out?

    • Dave Rongey says:

      Hi Suzy,
      From what you have described it sounds like you have installed lamp socket adapters that have a photocell in each unit, therefore the first unit will go on and produce light that will cause the other two photocells to sense the light and react as if it were daylight. To fix this problem you may consider removing the adapter units and purchase a single photocell that would fit onto the base of the light fixture. Installing the photocell will require drilling a hole to into the light fixture and connecting the light fixture power wire through the photocell control.
      I hope this helps you,

  7. Fred Collins says:

    I have a dusk to dawn led light that comes on perfectly at night, but during the day it strobes all day. It blinks all day and then comes on at night. At dusk it looks like a disco ball until it comes completely on. What could be the cause of this?

    • Dave Rongey says:

      Hi Fred,
      Make sure the lamps are the right type as specified by the light fixture manufacturer. For example: If the lamps are supposed to be incandescent or halogen, and CFL or a non compatible lamp is installed then it may cause the dusk to dawn fixture not to work normally.
      I hope this helps,

      • fred collins says:

        They were manufactured as led. There is no bulb to screw in, there are about 40 small led on the light, and they just strobe all day.


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