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Soffit floodlights © D Friedman at InspectApedia.com Outdoor Floodlight Diagnosis & Repair
How to 120V repair outdoor light fixtures

This article describes diagnosing & fixing an outdoor light that is not working.

Here we explain & illustrate how to inspect and test a dawn-to-dusk floodlight or security light that is not working. Starting with how to use a neon tester to confirm that electrical power is off before touching electrical wires, we continue with a list of things to check if your outdoor light won't turn on.

This article series discusses outdoor lighting installation, troubleshooting and repair procedures. This series also explains how to install recessed lights in an exterior soffit or roof overhang. We provide lighting installation suggestions about the type of light fixture to use, light fixture support, clearances, fire safety, moisture resistance, switch location, and electrical code citations for exterior lighting on buildings.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

How to diagnose & fix an outdoor "Dusk to Dawn" motion-sensor light fixture that won't light-up

Dawn to dusk outdoor light stopped working (C) Daniel FriedmanBelow in a series of steps we show how to test the operation of outdoor dawn-to-dusk light fixtures to diagnose just about any malfunction. By "outdoor" light fixtures we include lights that may be enclosed or recessed in a soffit, mounted on a wall, or atop a pole or similar independent support.

These same diagnostics will troubleshoot other outdoor lighting such as floodlights and security or motion-sensor lights regardless of whether or not the light includes a dawn-to-dusk feature.

Reader Question:

2016/04/03 Freezing Cold said:

Without warning, our outdoor dusk to dawn light stopped working Tried cleaning the fixture's sensor & changing floodlight bulbs, but that didn't help.

Any ideas or suggestions? Or is this 3-year old fixture a goner? Thanks.

This question appeared originally at: ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR

Here are the steps to diagnose & fix a floodlight, motion-sensor light, security or dawn-to-dusk outdoor light that is not working:

Reply: Watch out: some of these inspection steps or bulb socket repair attempts must be done with electrical power turned off. Otherwise there is risk of death by electrocution; if you don't know how to do this safely ask for help from a licensed electrician as you could be killed.

Article Contents

Turn off Electrical Power and Confirm that Electricity is OFF at the Fixture Before Touching It

Confirm that the neon tester is working before trusting it with your life (C) Daniel Friedman

[Click to enlarge any image]

A simple and very inexpensive tool such as a Neon Tester lamp can be used to determine if electrical power is on or off at an electrical wire or device before it is handled. Having been surprised once by discovering that my tester itself had failed, now before checking the status of an un-certain electrical circuit, I confirm that my neon tester is working normally by inserting its probes into a known-live electrical receptacle - illustrated above.

Using a neon tester to check for power at electrical wires (C) Daniel Friedman

In our photograph above the neon tester's leads are touched to the line and neutral wires and the bulb is LIT indicating that electrical power is ON at this circuit. In our next photo below you can see that the neon tester's light is OFF indicating that power has now been turned OFF.

Watch out: this is not a reliable nor a complete electrical system test. For example, a weakly-grounded wire or electrode may look just fine when tested with a VOM, a DMM, or a neon tester, but when subject to higher current flow the ground may be completely inadequate.

Using a neon tester to check for power at electrical wires (C) Daniel Friedman

Watch out: some of these inspection steps or bulb socket repair attempts must be done with electrical power turned off. There is risk of death by electrocution; if you don't know how to do this ask for help from a licensed electrician as you could be killed.

More safety advice is

at TEST EQUIPMENT, ELECTRICAL

Inspect the Outdoor Fixture Before Starting Tests

Here is a list of outdoor light installation snafus that might upset a licensed electrician as well as your local electrical inspector. All of these conditions were found at the same "not-working" outdoor light.

Leaks into the light's electrical box mount

Water leaks into electrical fixture outside (C) Daniel Friedman

Before closer inspection of the wiring and bulb socket on the "Dawn-to-Dusk" floodlight fixture discussed in this article I took a look at how the fixture was mounted on the wall. Above my screwdriver tip is pointing to an opening into the wall above this surface-mounted outdoor light.

I didn't see any sign that a weatherproof electrical box had been used for this installation, so I already suspected that I would find amateur electrical wiring that may be unsafe.

Improper mounting screws for the outdoor light

Drywall screw used at outdoor light fixture (C) Daniel Friedman

A second warning sign that my cousin Neil might have done this light installation and wiring (Neil is a good guy but not so handy) was the use of interior drywall screws to mount the light fixture to the wooden clapboard wall.

Interior Work Electrical Box used at an Outdoor Light Fixture

Interior work electrical box exposed to the weather (C) Daniel Friedman

Aside from electrical code violations and risk of water entry that short-circuits the light fixture, making it unsafe even to touch, leaks into the building wall at this sloppy light installation risk longer term structural damage from rot or from having attracted wood-destroying insects.

Electrical Box Not Secured to Wall

Improper securing of electrical box to wall -  loose (C) Daniel Friedman Improper securing of electrical box to wall -  loose (C) Daniel Friedman

Woe continued at this electrical job. The electrical box was "secured" to the wall simply by having driven electrical wire staples into the wall through one of the box ears.

The box was loose in the wall and neither of these staples at the box top and bottom was holding it in place. I could pull the staples out or the whole box with two fingers and a little tug.

Damaged Gasket Seal at the Outdoor Light Fixture

Damaged floodlight gasket allows leaks into the electrical wiring (C) Daniel Friedman

Finally the gasket that was intended to seal this outdoor floodlight to its electrical box mount was itself so deteriorated that water readily entered the fixture, its wiring, and the "electrical box" behind it.

We decided to install a new wet-location electrical box on this wall, mount a new motion-sensor floodlight fixture to the new box, and of course to seal the box to the wall.

Diagnosis: Check for These Security Light Problems

Review these checks and tests in about the order given to find out why your light is not working. I'm listing steps in an order guided by a guess at probability of the problem cause along with ease or simplicity of each step.

  1. The bulb: take a bulb that's known to be working - you saw it lit on a fixture - and try it in the fixture - if it won't light then try it again in the fixture where it was working to confirm the bulb is still good, OR try the existing light's bulb in an indoor fixture - we want to avoid looking dumb because we had a bad bulb
  2. Switches: check that all relevant switches are on
  3. Electrical power: check for electrical power right at the fixture, using a DMM, VOM, or neon tester.

    Watch out: if you don't know how to do this ask for help from a licensed electrician as you could be killed.
  4. Corroded electrical lamp socket base or sides: if your outdoor light or floodlight is flickering or goes out entirely the cause may be the obvious ( a burnt-out bulb) but it might be more subtle: corrosion in the bulb socket.

    Test the floodlamp bub in another fixture: if the bulb lights then the problem is in the bulb socket or the fixture itself.

    With electrical power to the light switched OFF and confirmed as OFF using a neon tester or other test device, try cleaning, scraping, sanding the bulb contact points and then using a small screwdriver, gently lift the center contact point a few millimeters up to assure that it makes good contact with the bulb base.

    Watch out: if you don't turn power off before trying to clean up or replace a bulb fixture you could be shocked or killed.

Split bulb socket caused failure of this outdoor floodlight (C) Daniel Friedman 2016

  1. Cracked lamp socket: If the fixture still won't light check for a cracked or damaged bulb socket such as the damaged floodlamp socket shown in my photo above.
  2. Bulb base: some new bulbs, including some LED units sold as outdoor floodlamps are manufactured with a shorter bulb-base than older lamps.

    Some of these short-based bulbs also feature a shoulder at the top of the threaded bases. The bulb shoulder may contact the top of the lamp socket before the tip contact on the bulb's base contacts the electrical contact in the bottom of the lamp socket.

    Sometimes, with power off to avoid being shocked, you can gently pry up the tab in the bottom of the bulb socket base to make better contact with the bulb.

    Also try using an older style incandescent bulb just to test for contact and lighting.
  3. Manual "on": If the fixture has power and the bulb is good, use the motion/sensor or control for the light to put it into "TEST" mode. That should bypass the automatic control and force the light on.

    If the Manual ON switch doesn't illuminate the light, someone who can follow the wires can bypass the sensor - if the fixture lights, then you know you need to replace just the sensor assembly.
  4. Internal wiring or splice disconnects: disassemble the light from its mounting base or electrical box and check each of the spliced or twist-on connector connections therein.

    A broken wire may or a very corroded connection in an electrical box that was not weather-tight might explain why the light was not working. Below I've disassembled the black "line" wiring in preparation for re-making that electrical connection. Notice that an electrical ground is not visible in this fixture.

    Ultimately we installed a new floodlight at this location. That installation is detailed

    at SECURITY / MOTION SENSOR LIGHT INSTALL .

    Watch out: work with electrical power off; if you don't know how to do this, ask for help from a licensed electrician as you could be killed.

Check twist on connector splices in a motion sensor light that's not working (C) Daniel Friedman Check twist on connector splices in a motion sensor light that's not working (C) Daniel Friedman

  1. Replace the light fixture: as a last resort, change the whole fixture along with its sensor.

    Please see SECURITY / MOTION SENSOR LIGHT INSTALL for complete details on how to replace or install a new outdoor security light or floodlight with a motion detection sensor.

...




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2021-06-04 by (mod)

@sean o sullivan,

If it's one bulb with half its elements out, the bulb has failed and needs replacement.

If there are two bulbs and one is off, most-likely the bulb has failed, though there could also be a failed electrical connection inside the light fixture electrical box.

On 2021-06-04 by sean o sullivan

why is only half my led floodlight lighting

On 2021-05-16 by My 3 Dogs

Thanks.

On 2021-05-12 by (mod)

@ Dogs,

I think you're describing an intermittent electrical problem that may be a wiring connection, splice, or switch or control that needs repair or replacement. Ask your electrician to trace the circuit and look for those troubles before replacing the fixtures themselves.

On 2021-05-11 by My 3 Dogs

Non-motion non-dusk to dawn outdoor flood light fixtures with halogen bulbs.

I have two outdoor fixtures one on the side of the house and one on the back of the house, that the (if looking at) right side bulb comes on then goes out or doesn't come on at all, when I turn it on. Both of these light fixtures are on different wall switches. I thought it was the bulbs so I replaced them. Same thing happened.

I replaced both fixtures with new ones of the same type. Same thing happened. I am wanting to replace these fixtures with new motion type with security cameras but I'm afraid that the same issue will exist. I know that this must be a common issue with a problem or fix, because I've seen it posted.

Any idea if this is a power source or fuse box issue?

On 2021-02-24 by (mod)

@Anonymous, without a shred of information about your building I don't think I can offer useful answer to why your lights don't work but an electrician would start at the electrical panel looking for a tripped circuit breaker or blown fuse and then she would trace a circuit forward to see if you have an open connection.

On 2021-02-24 by Anonymous

All my exterior lights stopped working since we have had a very cold week, why?

On 2021-02-07 by (mod)

Anon

Take a look at what actual time you are seeing your security light on bright vs dim; some security lights can be programmed to turn on at a "dim" or low light level and will brighten if the light's motion sensor is tripped.

Then take a look at the instructions for your security light brand and model to see if it has the "dim-on" feature I describe as that can then be set to your preference.

On 2021-02-07 by Anonymous

Led security light will come on some nights and other nights will have a dim glow only and then will possibly come on in the middle of night and sometimes does not come on

On 2021-01-19 by (mod) - outdoor dusk to dawn flood light that stopped working. Tried new bulb and that didn't work.

Robert

Is it possible that the problem is the bulb socket?

Check for a corroded or broken bulb socket.

On 2021-01-19 by Robert A.

Had an outdoor dusk to dawn flood light that stopped working. Tried new bulb and that didn't work. Fixture/wiring seemed to be ok as well as confirmed power running to fixture. Bought new LED fixture and light still won't come on in total darkness. Am I missing anything? Thank you.

On 2020-11-16 1 - by (mod) -

Apologies Jeffrey but I don't understand the question. Choke?

On 2020-11-16 by Jeffrey owusu

Do 3 eye flood light have choke?

If yes! How does it look light. Thank you.

On 2020-09-18 - by (mod) -

Check the switches the set up the floodlight and are found Ali's underside. Some floodlights have a daytime mode leaves leaves the light on dim. You can turn that off

On 2020-09-18 by rami

I have a flood light in my back yard sometimes turn off but no completely, after 15 minutes turn back on.Some can help me thank you.

On 2020-09-13 - by (mod) -

Scotty

I've seen quick bulb failures from

- poor quality bulbs (made you know where)

- loose or damaged wiring - this is the most-common cause as a bad or overheating connection can cause flickering - sometimes not so visible to humans - that tortures the bulb filament into an early demise

- voltage surges

- wet electrical connections

On 2020-09-13 by Scotty

Put new sensor on top of light.
Blows bulb after one night.
Any thoughts??

On 2020-08-21 by Anonymous

What would cause an outdoor censored floodlight to dim when you screw in the 2nd bulb

On 2019-12-28 by (mod) -

Start by putting in a bulb that's known to be good by having tested it in an another fixture. That can also confirm that you have power to the light.

On 2019-12-28 by Anonymous

Sensor outside lights , just lids once then is dead, ive checked all lights they are fine, day night sensor was removed , lights still off what can the problem be

On 2019-11-08 by (mod) -

Karen

Sometimes the socket itself is damaged - I've seen the socket shell split - so that it will no longer hold the bulb. That may be what happened to yours; see if you can snap a photo without getting shocked or falling off a ladder, and look for a split in the screw-in shell.

TAKE CARE don't stick a tool or finger into the socket or you can be shocked or killed. Work with POWER OFF.

By the way it may be cheaper to replace the floodlight, but those sockets can be replaced.

On 2019-11-08 by Karen

I tried another bulb but same results.

On 2019-11-08 2 by Karen

Why would an outdoor house roof flood light suddenly stop from its socket? It was a working bulb so I tried to screw it back in n but it would not hold! The bulb will not screw into the socket like it always has! Should a flood light bulb simply drop from the socket?

On 2018-11-28 by (mod) -

Wilda

Have you tried replacing the bulb?

On 2018-11-27 by Wilda Oranje

I have a large yard light is dust to dawn, it stopped working, I don't know if its the bulb or the sensor... Please ...Asap.

On 2018-08-24 by Gerri

My 5 yr old motion sensor light stop working after playing with it it came back on after I plug it back up stayed on five minutes went back out but it want come on if walking by it only when it’s unplug and plug back up

On 2018-07-18 by (mod) -

Tom

Even though some switches and sensors that get wet will dry out and appear to work normally for a time, in my experience ultimately corrosion from even a single wetting will usually lead to control or switch failure. I'd replace the sensor - you can purchase just that part and don't have to replace the entire fixture.

Example: here is a white replacement motions detector for an exterior light, from Cooper Lighting MS180W Motion Sensor-300W

IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2018-07-18 by Tom Jones

Will the sensor fail completely ones it gets water on the inside? The light still goes on and off again after a few minutes once it's switched on from the main supply but fail to do so again after the first time. Then it staya off. Please help

On 2017-12-08 by (mod) -

it's possible that the sensor has failed

On 2017-12-07 by Dennis Brohm


I have a daylight and nighttime sensor that turns the lights on in my building . It seems to be staying on in the day time now . Not sure what the issue is .


...

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