What you need to do before you start

Replacing an outdoor light fixture is a straightforward job that takes about 30 minutes once you have the right tools and parts. The basic steps are: turn off power at the breaker, remove the old fixture, disconnect the wires, install a mounting bracket, connect the new fixture's wires to the existing ones, and find the new fixture to the bracket. Most homeowners can do this without calling an electrician, as long as the power is off and you follow the manufacturer's instructions for your specific fixture.

Before you buy a replacement, measure the hole or mounting area where the old fixture sits. Take a photo of how the wires are connected—this matters because you will need to match them when you install the new one. If the old fixture has been there for years, the wires inside the wall may be corroded or brittle, so handle them gently.

Check whether your new fixture comes with a mounting bracket. Most do, but some require you to reuse the old one. If you are replacing a fixture that was installed decades ago, the old bracket may not fit a modern fixture, so you may need to buy a separate bracket that matches your new fixture's base.

Key Takeaways

  • Turn off power at the breaker before you touch any wires, and test the fixture with a non-contact voltage tester to confirm the power is off.
  • Take a photo of the wire connections before you disconnect anything, so you know which wires go together when you install the new fixture.
  • Match wire colors: black to black, white to white, and bare copper or green to the ground screw or green wire on the new fixture.
  • Use wire nuts (the plastic connectors) that come with your new fixture, or buy new ones if the old ones are cracked or loose.
  • If you are uncomfortable working with electrical wires or if the fixture does not have a ground wire, call a licensed electrician.

Turn off the power and test it

Go to your electrical panel and find the breaker that controls the outdoor light. It is usually labeled "porch light," "exterior light," or "front light," but if you are not sure, flip the breaker and have someone check whether the light goes off. Once you flip the breaker, test the light switch to make sure it does not turn the light back on. The light should stay off.

Before you touch any wires, use a non-contact voltage tester—a small handheld tool that beeps or lights up when it detects electricity. Hold it near the wires inside the fixture. If it beeps, the power is still on. Do not proceed. Go back to the panel and flip the correct breaker. If the tester does not beep, the power is off and it is safe to work.

Non-contact voltage testers cost $10 to $25 and are worth buying for any electrical work. They are sold at any hardware store and are safer than touching wires to test them yourself.

Remove the old fixture

Most outdoor fixtures are held up by two or three screws that go through a mounting bracket into the wall. Unscrew these and carefully lower the fixture. You may need to support it with one hand while you unscrew with the other, or ask someone to hold it steady.

Once the fixture is loose, you will see the wires inside. There are usually three: a black wire (hot, carries power), a white wire (neutral, completes the circuit), and a bare copper or green wire (ground, a safety wire). These wires are connected to the wires in the wall using wire nuts—plastic connectors that twist onto the joined wires to hold them together.

Untwist each wire nut by turning it counterclockwise. The wires will separate. Gently pull the old fixture away from the wall. If the wires are stuck or the fixture does not come free easily, do not force it—there may be caulk or paint holding it. Use a utility knife to cut around the edge of the fixture base, then try again.

Prepare the mounting bracket

Once the old fixture is off, look at the mounting bracket left behind on the wall. If your new fixture comes with its own bracket, you will need to remove the old one. It is usually held by two bolts that go through the wall into the electrical box behind it. Use a wrench or socket to unscrew these bolts, and the old bracket will come free.

If the old bracket is in good condition and your new fixture's base fits it, you can leave it in place. Check by holding the new fixture up to the bracket and seeing whether the screw holes line up. If they do, you can reuse it and skip ahead to the wiring step.

If you are installing a new bracket, position it so the screw holes are centered on the electrical box. Use the bolts that come with the new bracket, or if you are reusing the old ones, make sure they are tight. The bracket should not move when you push on it.

Connect the wires

Before you connect anything, strip about half an inch of insulation from the end of each wire if the ends are damaged or corroded. Use a wire stripper tool—a small handheld tool with a slot that cuts the plastic coating without damaging the copper underneath. If the wire ends look clean and shiny, you do not need to strip them.

Hold the black wire from the wall next to the black wire from the new fixture. Twist them together clockwise two or three times, then screw a wire nut onto the joined wires. Turn the nut clockwise until it is snug—it should not come off if you tug gently on the wires. Repeat this for the white wires, then the ground wires.

If the new fixture has a green wire and the wall has a bare copper wire, connect them together. If the new fixture has a green wire and there is no ground wire in the wall, this is a sign the circuit is older and may not be grounded. You can still install the fixture, but it is safer to have an electrician check the circuit first. Do not ignore a missing ground wire.

Once all three connections are made and the wire nuts are tight, gently push the wires back into the electrical box. They should fit without being cramped. If the box is too full, do not force the wires—call an electrician to assess whether the box is large enough for the new fixture.

find the fixture to the bracket

Hold the new fixture up to the bracket so the screw holes line up. If the fixture is heavy, have someone hold it while you start the screws. Use the screws that come with the fixture—they are usually sized to fit the bracket holes. Screw them in by hand first, then tighten them with a screwdriver. Do not overtighten; the fixture should be snug but not so tight that you crack the base.

Once the fixture is secured, install the light bulb and any glass or plastic cover that came with it. Check the manufacturer's instructions for the maximum wattage bulb the fixture can handle. Using a bulb that is too powerful can overheat the fixture and shorten its life.

Go back to the electrical panel and flip the breaker back on. Turn on the light switch. The light should come on. If it does not, turn the breaker off again and check that all wire nuts are tight and that the wires are fully inserted into the electrical box.

Seal the gap between the fixture and the wall

Once the fixture is working, look at the gap between the fixture base and the wall. If there is a gap, water can seep behind the fixture and cause damage. Use exterior caulk—a waterproof sealant made for outdoor use—to fill the gap. explore it with a caulk gun, smooth it with a wet finger, and let it dry according to the product instructions (usually 24 hours).

Do not use interior caulk or silicone caulk meant for bathrooms. Exterior caulk is formulated to expand and contract with temperature changes and to resist UV damage from sunlight. It is sold at any hardware store and costs $5 to $10 per tube.

When to call a licensed electrician

Call an electrician if the power does not turn off at the breaker, if you find more than three wires in the fixture, if the wires are damaged or corroded beyond what a straightforward strip can fix, or if the electrical box feels loose or damaged. Also call if the new fixture requires a different circuit than the old one—for example, if you are upgrading to a fixture that draws much more power.

If you are not comfortable working with electrical wires at any point, stop and call. Electrical work done incorrectly can cause a fire or shock hazard. A licensed electrician will charge $100 to $300 for a fixture replacement, which is worth the cost if you are unsure.

Frequently Asked Questions

Do I need a permit to replace an outdoor light fixture?

Most jurisdictions do not require a permit for replacing an existing fixture with one of the same type and wattage. However, some areas require a permit if you are upgrading to a fixture that uses significantly more power or if you are adding a new circuit. Check with your local building department before you start if you want to be certain.

What if the old fixture is stuck and won't come off?

Caulk or paint may be holding it. Use a utility knife to cut around the edge of the fixture base, cutting through the caulk or paint. Let the knife sit for a minute to soften the material, then try to pry the fixture gently with a flat screwdriver. Do not force it or you may crack the wall.

Can I use the old wire nuts on the new fixture?

If the old wire nuts are in good condition—not cracked, loose, or corroded—you can reuse them. However, most new fixtures come with wire nuts sized for their wires, so it is safer to use the new ones. Wire nuts cost less than $1 each, so replacing them is inexpensive insurance.

What size bulb should I use in the new fixture?

Check the label inside the fixture or the manufacturer's instructions. It will say something like "60W maximum" or "LED only." Use a bulb that meets this limit. LED bulbs use less power and last longer than incandescent bulbs, so they are a good choice for outdoor fixtures that are hard to reach.

Why is my new fixture not turning on even though the breaker is on?

Check that all three wire nuts are tight and that the wires are fully pushed into the electrical box. Also check that the light bulb is screwed in all the way and that the switch is in the on position. If the bulb is good and the switch works, turn the breaker off and recheck the wire connections.