There are few things more frustrating than pulling into your driveway and seeing half your landscape lighting dark. The system worked perfectly last month. Nothing changed. And yet here you are, staring at a beautifully lit front bed on one side and a black hole on the other.
The good news is that landscape lighting failures follow patterns. After enough years working on systems across Houston, Katy, Sugar Land, and Richmond, the same handful of causes come up again and again. This guide walks through each one, what it looks like from your driveway, and what it actually takes to fix.
Start Here: What Exactly Is Failing?
Before assuming the worst, narrow down the symptom. The pattern of what is dark tells you a great deal about where the fault lives.
Nothing works at all
If every fixture is dark, the problem is almost certainly at the source rather than in the yard. Check that the transformer is plugged in and receiving power, that the GFCI outlet it sits on has not tripped, and that the timer or photocell has not lost its settings. A tripped GFCI after a heavy Gulf Coast storm is one of the single most common causes of a totally dark system, and it costs nothing to reset.
One section is dark, the rest works
This is the classic buried-wire failure, and it is the most frequent repair we perform. When one run goes out while other runs stay lit, the fault is somewhere in the cable feeding that specific run — not in the transformer, which is clearly still working.
Lights flicker or cut in and out
Flickering is an electrical connection problem. Something in the path is intermittent: a loose connector, a corroded splice, or water that has made its way inside a socket. Flickering fixtures should be addressed promptly, because the arcing that causes the flicker also generates heat that will eventually destroy the socket.
Lights are dim or yellowing
Dimming across an entire run usually indicates voltage drop. Yellowing on individual fixtures usually means aging halogen lamps or a clouded lens.
The Six Most Common Causes in Houston
1. Damaged or Corroded Low-Voltage Wire
Buried cable takes more abuse than most homeowners realize. Landscapers edging beds slice through it. Tree roots pull splices apart. Someone plants a new shrub and puts a shovel straight through the run. And in Houston’s clay soil, which holds moisture for long stretches after rain, any splice that was not made with a properly sealed waterproof connector will corrode.
Corrosion is the silent version of this problem. It does not fail all at once. Resistance builds gradually at the connection point, the fixtures beyond it get progressively dimmer over months, and eventually the connection gives out entirely.
The fix: trace the run with a voltage meter to locate where power stops. Cut out the damaged section, re-splice with a genuinely waterproof connector — not a wire nut wrapped in electrical tape, which is what we find in a distressing number of failed systems — and rebury properly.
2. A Failed or Overloaded Transformer
The transformer converts household current down to the low voltage your fixtures run on. It is the heart of the system and, like anything electrical sitting outdoors in Houston humidity, it eventually wears out.
Quality transformers last ten to fifteen years. Cheap ones, and any transformer that has been run near its maximum wattage for years, fail considerably sooner. Overloading is extremely common: a system is installed with a 300-watt transformer running 280 watts of fixtures, then a few more lights get added over the years, and now the unit is running past its rated capacity every single night.
The fix: test the output voltage at the transformer terminals. If there is no output with power confirmed at the outlet, the transformer has failed. Replacement should always be sized with headroom — we generally recommend running no more than about eighty percent of rated capacity so there is room to add fixtures later.
3. Moisture Inside Sockets and Fixtures
This is Houston’s signature landscape lighting problem. Our humidity is relentless, and any fixture whose gasket has degraded or whose lens seal has cracked will take on moisture. Once water is inside the socket, you get corrosion on the contacts, intermittent operation, and eventually complete failure.
Cheaper fixtures fail this way much faster. Aluminum and composite housings develop hairline cracks as they expand and contract through Houston’s temperature swings, and once there is a crack, water gets in.
The fix: replace failed sockets, or replace the fixture entirely if the housing itself is compromised. This is one of the strongest arguments for solid brass — brass does not corrode the way aluminum does, and quality brass fixtures maintain their seals far longer.
4. Burned-Out Lamps
Sometimes the answer really is that simple. If a single fixture is dark and everything around it works, the lamp itself is the first thing to check.
This is far more common on older halogen systems. Halogen lamps have a relatively short service life and fail regularly, which is one of the most compelling reasons to convert an aging system to LED. An LED lamp rated for fifty thousand hours will outlast a halogen many times over.
The fix: replace the lamp. If you find yourself replacing halogen lamps constantly across the system, that is a strong signal it is time to consider a full LED conversion.
5. Failed Photocell or Timer
If your lights come on at strange hours, stay on through the day, or never turn on at all despite the transformer having power, the control system is the culprit.
Photocells sense darkness and trigger the system. They sit outdoors permanently and eventually fail, or get obscured by mulch, plant growth, or a coat of dust and pollen. Digital timers lose their programming during power outages, and many transformers have an internal backup battery that dies after a few years, at which point every outage resets the schedule.
The fix: clean or replace the photocell, reprogram the timer, and replace the backup battery. This is usually the fastest and least expensive repair on this list.
6. Voltage Drop from Overloaded or Undersized Runs
Voltage drop is the most misunderstood failure, because the system technically still works — it just does not work well. As current travels along the cable, voltage falls. Put too many fixtures on one run, or use wire that is too thin for the distance, and the fixtures at the far end receive noticeably less voltage than the ones near the transformer.
The visible symptom is a run where lights get progressively dimmer and yellower the further they are from the source. Homeowners often blame the bulbs, but the bulbs are fine — they are simply being starved.
The fix: rebalance the system. That may mean splitting one long run into two, upgrading to heavier gauge wire, moving fixtures to a different tap on the transformer, or converting to LED, which draws so much less current that voltage drop becomes far less of an issue.
What You Can Safely Check Yourself
There are a few things worth trying before calling anyone, and none of them require electrical work:
Reset the GFCI outlet the transformer is plugged into. Confirm the transformer is actually switched on and the timer has not been knocked off schedule. Wipe off the photocell if it is coated in dirt. Look for obvious physical damage where landscaping work has been done recently. Pull mulch away from fixtures that seem dim, since it takes surprisingly little buildup to block a beam.
Beyond that, diagnosis requires a voltage meter and knowledge of what the readings should be at each point. Low-voltage systems are safe compared to household current, but incorrect repairs cause failures that cost more than the original problem.
Repair or Replace? An Honest Framework
Not every struggling system is worth saving, and not every failing system needs replacing.
Repair makes sense when the fixtures are solid brass or high-quality copper, the majority of the system still works, the failure is isolated to wiring, a transformer, or a handful of fixtures, and the original design still suits your landscaping.
Replacement or major upgrade makes more sense when most fixtures are corroded aluminum or cracked composite, you are replacing several fixtures a year, the system is still halogen and you are constantly buying lamps, or the design no longer fits because your landscaping has matured dramatically since it was installed.
There is also a middle path that many Houston homeowners take: keep the wiring infrastructure, replace the fixtures with brass, and convert to LED. This is often far less expensive than a full tear-out, because the trenching and wire runs are the labor-intensive part.
Preventing the Next Failure
A genuinely well-installed system needs remarkably little intervention, but annual attention prevents nearly every emergency on this list.
Once a year, fixtures should be re-aimed — they shift over time from ground movement, lawn equipment, and curious pets. Lenses should be cleaned, because Houston’s pollen and humidity dull them noticeably within a season. Growth should be trimmed back from fixtures. Connections should be checked before corrosion becomes failure. And the transformer load should be reviewed if anything has been added.
Telling your landscaping crew where the wire runs are prevents a remarkable number of cut-cable calls. Most damage of this type is entirely accidental and entirely avoidable.
When to Call a Professional
Call for help when the transformer has no output, when an entire run is dead and you cannot locate the break, when fixtures are flickering, when you see any sign of scorching or melted plastic at a connection, or when you have simply replaced the same component more than once and want to know why it keeps failing.
At Ambiance Outdoor Lighting, we repair systems throughout Houston regardless of who installed them. Many of our repair clients came to us because their original installer went out of business or stopped returning calls. We diagnose the actual fault, explain what we found in plain language, and tell you honestly whether repair or upgrade is the better use of your money.
Frequently Asked Questions
1. How do I know if my landscape lighting transformer is bad?
If the transformer has power at the outlet but produces no voltage at its output terminals, it has failed. Other signs include a burning smell, visible scorching around the terminals, or a unit that trips its own internal breaker repeatedly. Before assuming failure, confirm the GFCI outlet has not tripped and the timer has not simply lost its program.
2. Why did half my landscape lights go out at once?
When one section fails while the rest stays lit, the fault is in the cable feeding that particular run rather than in the transformer. The most common causes are a cut from edging or digging, a corroded splice, or a connector that has let water in. Tracing the run with a voltage meter locates the break without digging up the entire yard.
3. Can I repair low-voltage landscape lighting myself?
You can safely reset a GFCI, reprogram a timer, clean a photocell, and replace lamps. Beyond that, diagnosis requires a voltage meter and knowledge of expected readings at each point in the system. Improper splices are the leading cause of repeat failures, because a connection that is not genuinely waterproof will corrode within a season in Houston’s climate.
4. How much does landscape lighting repair cost in Houston?
Service calls typically start around $250, which covers full system diagnosis and most straightforward repairs such as re-splicing wire or replacing lamps. Transformer replacement and larger repairs are quoted after diagnosis. Reputable companies provide pricing before starting work rather than after.
5. Why do my landscape lights keep burning out?
Frequent lamp failure usually points to one of three causes: halogen lamps, which simply have a short service life; voltage that is too high for the lamps because of an incorrect transformer tap; or moisture in the socket causing arcing. If you are replacing lamps across the whole system regularly, converting to LED usually solves the problem permanently.
6. What causes landscape lights to flicker?
Flickering is caused by an intermittent electrical connection — typically a loose or corroded splice, moisture inside a socket, or voltage drop from an overloaded run. It should be addressed quickly, because the arcing behind the flicker generates heat that eventually destroys the socket and can damage the fixture.
7. Is it worth repairing an old landscape lighting system?
It depends on the fixtures. Solid brass and quality copper fixtures are worth repairing almost indefinitely, since individual components are replaceable and the housings survive Houston’s humidity. If most fixtures are corroded aluminum or cracked composite, the ongoing cost of replacing them piecemeal usually exceeds the cost of upgrading properly.
8. How long should a landscape lighting system last?
A professionally installed system with brass fixtures and properly sealed connections should perform for fifteen to twenty years or more with routine maintenance. Transformers typically need replacing every ten to fifteen years, and lamps are consumable. Budget systems with aluminum fixtures often need major work within five to seven years in Houston’s climate.
9. Will my homeowners insurance cover landscape lighting damage?
Coverage varies significantly by policy. Damage from a covered event such as a storm may qualify, while gradual failure from corrosion, wear, or age generally does not. If a contractor cut your wire during other work, their liability insurance is usually the appropriate route. Check your specific policy language before assuming coverage.
10. Can you fix a system installed by another company?
Yes. Most professional lighting companies, including ours, service systems regardless of who installed them. We work on all major low-voltage brands. This is common in Houston, where homeowners frequently inherit systems from previous owners or from installers who have since closed.