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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.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
How to diagnose & fix an outdoor "Dusk to Dawn" motion-sensor light fixture that won't light-up
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.
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.
Turn off Electrical Power and Confirm that Electricity is OFF at the Fixture Before Touching It
[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.
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.
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.
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
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
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
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
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
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.
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
Switches: check that all relevant switches are on
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.
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.
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.
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.
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.
Replace the light fixture: as a last resort, change the whole fixture along with its sensor.
 Codes & Standards pertaining to fire-rating enclosures:
UL 263 (also see Canadian CUL specifications)
 Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com.
 New Jersey State Energy Code, N.J.A.C. 5:23-3.18, Recessed Lighting Fixtures (RLFs), Uniform Construction Code Communicator, Vol. 16, No. 1, Spring 2004, p. 8, Division of Codes and Standards, POB 802, Trenton NJ 08625-0802. Web site for free downloads of the energy
compliance tools REScheck, New Jersey edition and
COMcheck-EZ is www.energycodes.gov.
N.J.A.C. 5:23-3.18 adopts by reference the 1995
edition of the Council of American Building Officials’ Model
Energy Code (CABO MEC/1995) as New Jersey’s Energy
Subcode of the Uniform Construction Code. Sections 502.3.4 and 602.3.3 of CABO MEC/1995, both entitled
“Recessed Lighting Fixtures,” contain requirements for RLFs
in relation to the Energy Subcode. The following are the
three options for the installation of RLFs when installed in
the building envelope. Only one must be followed to meet
the requirements of the Energy Subcode:
1. Type IC rated, manufactured with no
penetrations between the inside of the recessed
fixture and ceiling cavity, and sealed or gasketed to
prevent air leakage into the unconditioned space; or
2. Type IC rated or non-IC rated, installed inside a
sealed box constructed from a minimum ½-inch-thick
gypsum wall board or constructed from preformed
polymeric vapor barrier, or other air-tight assembly
manufactured for this purpose, while maintaining
required clearances of not less than ½ inch from
combustible material and not less than three inches
from insulation material; or
3. Type IC rated, in accordance with ASTM E 283-
91 (Standard Method of Test for Rate of Air Leakage
Through Exterior Windows, Curtain Walls, and
Doors), with no more than 2.0 cfm air movement from
the conditioned space to the ceiling cavity. The
lighting fixture shall be tested at 75 Pa or 1.57 lbs/ft2
pressure difference and shall be labeled.
Sections 502.3.4 and 602.3.3 of CABO MEC/1995
are the responsibility of the building subcode official, who
inspects RLFs to ensure that they are either insulation cover
rated (IC rated), or installed in a sealed box that has the
insulation at least three inches from the light fixture. It is
the building subcode official’s responsibility to ensure
compliance, both in the inspection plan review and inspection
plan review stages, because RLFs pose a potential fire
hazard if installed incorrectly with insulation. These fixtures
also act as chimneys, transferring heat loss and moisture
through the building envelope into attic spaces if not installed
properly. The heat loss resulting from improperly insulated
RLFs can be significant.
NOTE: Electrical subcode officials are responsible
for the wiring methods of RLFs.
 "Out of Sight, Out of Mind - the dangers and requirements of recessed light fixtures", Kellie K. Speed, Electrical Contractor, Feb. 2009, Quoting:
When installing recessed fixtures, carefully consider the location of the units. The presence of combustible materials surrounding
the luminaire is very important, and recessed lights can act as chimneys for heat loss and moisture transfer into attic spaces. Many
residential fires have resulted from improperly installed or modified recessed light fixtures, but they can be easily avoided.
In older homes that may have existing recessed lighting fixtures, homeowners sometimes cover these fixtures with insulation. As a
result, the insulation traps the heat created by the bulb and either melts the insulation on the electrical wiring or ignites combustible
materials, which is, of course, a fire hazard.
It is vital to ensure the area surrounding the recessed fixture is insulated properly. In addition to fire, the interior of a property could be compromised if air leakage occurs,
resulting in moisture, condensation and mold. Sealing the building properly reduces air movement in and out of the building. Uncontrolled air movement will negatively
impact the heating and cooling systems, resulting in higher initial and ongoing maintenance costs.
There certainly is a lot to consider when installing recessed lighting. For help, consult the National Electrical Code (NEC). Article 410 Parts M and N offer special
provisions for recessed luminaires installed in walls or ceilings. Most of these Code requirements are designed to protect combustible building materials from
temperatures greater than 90°C (194°F).
 National Electrical Code, (NEC). Article 410 Parts M and N:
provisions for recessed luminaires installed in walls or ceilings.
 "E-Series LED Recessed Light, Installation instructions for E6-E26-30-WH, retrofit installation or new construction installation, American Lighting, www.americanlighting.com
 "Information Bulletin - Recessed Light Fittings", ACE Insurance Limited, CU1-3, Shed 24, Princes Wharf, Auckland 1010, website: http://www.aceinsurance.co.nz/,
Ace reported a "near miss" inner city apartment complex fire traced to recessed light fittings. Quoting:
An investigation into the cause of a fault on an apartment complex’s fire alarm system revealed the cause
as a slow smouldering fire involving the heat detector wiring. Further investigation indicated the probable
cause of the fire to be due to a nearby recessed incandescent light fitting which had overheated. The
insulation on the electric wiring at the point of connection to the light fitting had been burnt away and the
burning had continued for several metres along the electrical wiring to the switch and another
interconnected light fitting within the same room. Thermal insulation material (fibreglass batts) was
present in the roof space around the recessed light fittings.
The recessed light fittings had been installed in the room for more than 15 years without any previous
issues. Repairs to the roof had been carried out some 5 years previously which required contractors to
access the roof space directly above the room.
Australian/New Zealand Wiring Rules (AS/NZS 3000:2007 provides minimum clearance for recessed light fittings but emphasizes that The importance of following relevant codes and standards and the recessed light manufacturer's installation requirements cannot be over-emphasized.
Clearance - luminaire to building element above
Side clearance - luminaire to structural member
Clearance -luminaire to thermal insulation
Clearance - luminaire to supply transformer
 E.Z. Barrier, fire-rated: Fire-rated Recessed Light Enclosure, E.Z. Barrier, 901 N 3rd St, Ste 130
Minneapolis, MN 55401
Ph. 612.436.0606 Fax 612.436.0608
firstname.lastname@example.org, Website: www.ezbarrier.com Product literature describes one-hour rated enclosure for recessed lights that save time over a site built fire-rated recessed light enclosure complies with the fire resistance codes listed in citation  above.
 "Wiring Methods Utilizing Suspended Ceilings (Revised", State of Oregon, Building Codes Division, code interpretation, 10/1/2002, Gary A. Wilson, Chief Electrical Inspector & Doug Alexander, Structural Code Specialist. This interpretation specifies that in light duty systems certain light fixtures (such as recessed fluorescent lighting), the ceiling system shall not be used for the support of the lighting fixtures. Intermediate-duty ceilings may be used for supporting recessed lighting fixtures provided certain support detail specifications are followed. Heavy duty ceiling systems require that the recessed light fixture be secured to specifications included in the interpretation. Web search 4/29/12, original source: http://www.etnews.org/docs/wiring_methods_suspended_ceilings.pdf
 "Recessed Light (Non-Insulating), Installation Instructions, CANARM Lighting & Fans, Tel: 800-265-1833 (English) or 800-567-2513 (French) or 800-267-4427 (USA) describe a recessed light fixture retrofit through a drywall ceiling.
 "Downlights, Recessed Downlight Housings - Installation", Lucifer Lighting Company, 414 Live Oak St., San Antonnio TX 78202, Tel: 210-227-7329, www.luciferlighting.com
 "Outdoor Recessed Light Kit Installation Instructions, apply to downlights / stair lights", Dekor, 2655 Santa Fe Unit 4H, Denver CO 80223, 2011, Customer Support: 800-258-0344, Website: www.DE-Kor.com. This document describes installation for a 12V DC constant current 3A transformer with a waterproof design IP66-rated, UL and CUL approved, and LED lighting fixtures that are waterproof and can be submerged in water. cf: OUTDOORRecessedLight Install1.pdf
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
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The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
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