Landscape Lights Not Working? A Troubleshooting Checklist

When a landscape lighting system goes dark, the cause is almost always something simple and fixable rather than a total failure. Low-voltage systems are wonderfully forgiving, but they live outdoors in soil, mulch and weather, so connections loosen, bulbs reach the end of their life, and electronics occasionally need a reset. Working through the system in order, from the wall outlet outward, will isolate the problem faster than guessing.

Start at the power source

Confirm the transformer is actually receiving power. Check that the GFCI outlet it plugs into has not tripped, that the breaker in your panel is on, and that any switch controlling the outlet is in the right position. A tripped GFCI is the single most common reason an entire system fails at once, and resetting it takes seconds.

If the transformer has an on/off switch or a manual override, set it to ON and listen for a faint hum or look for an indicator light. No life at the transformer points to power supply or transformer issues rather than anything in the yard.

Check the timer or photocell

Many systems only switch on at dusk through an astronomic timer, a photocell or a smart controller. If the lights stay off after dark, the timer may have lost its programming after a power outage, the clock may be wrong, or a photocell could be covered, dirty or aimed at a porch light that fools it into thinking it is still daytime. Reprogram the timer and clean or reposition the sensor.

Isolate whole-system vs. single-light failures

If every fixture is dark, the problem is upstream at the transformer, timer or a main wire run. If one fixture or a small cluster is out, suspect a failed bulb, a corroded connector or a damaged cable nicked by a shovel or aerator. Replacing a single bulb is an easy homeowner fix; tracing an intermittent cable fault often is not.

Voltage drop can also dim or kill the fixtures farthest from the transformer. If the lights nearest the transformer are bright but the far ones are weak or dark, you may have a voltage or wiring layout problem rather than a bad fixture.

Before reaching for tools, do a quick visual sweep in daylight: look for chewed or exposed wire, connectors pulled apart by frost heave, fixtures knocked loose by a mower, and water sitting in fixture housings. A surprising number of outages are visible once you know what to look for.

If you have reset the power, confirmed the timer, swapped a suspect bulb and cleaned the connections but the system still will not light, it is time to call a professional. Repeated GFCI trips, a transformer that buzzes loudly or smells hot, or a buried cable fault are not DIY territory. JHL Landscape Lighting services and repairs low-voltage systems across the Main Line, Delaware County and Chester County, including systems originally installed by other companies. If you would like a professional to diagnose the issue, reach out for a service visit and we will get your nights glowing again.

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