A few weeks ago we got a call from a homeowner in Essex County. Half the landscape lighting in the yard was dark. The other half worked fine. The system was installed roughly 20 years ago, and the company that put it in was long gone.
No diagrams. No labels. No photos. Nobody to call. Just a transformer on the garage wall with a fistful of unmarked cables disappearing into the ground, and two decades of gardens, fence posts, and regrading sitting on top of whatever was buried down there.
To be fair to the original installer, that was standard practice at the time. Almost nobody documented landscape lighting in the early 2000s. The work itself was actually solid. It ran for 20 years, which is more than you can say for most things with a power cord.
But standing in that driveway with zero context, we were reminded why we run our projects the way we do. This post is about both halves of that story: how you diagnose a system nobody understands anymore, and what should get left behind so nobody ever has to do that again.
What Low Voltage Landscape Lighting Actually Is
A quick primer, because it matters for everything that follows. A landscape lighting system starts with a transformer, usually mounted in the garage or on an exterior wall. It steps your household power down to 12 or 15 volts. From there, cable runs leave the transformer, get buried a few inches under the soil, and feed the fixtures spread around your property.
That low voltage is the good news. The system is safe to work on, safe to test live, and safe to have buried in a yard where kids and dogs dig holes. It is why a system like this can be diagnosed without an electrician's permit and why it is so forgiving for decades.
The bad news: because the cable is shallow and the connections live underground, the system is exposed to everything that happens in a yard over 20 years. And a lot happens in a yard over 20 years.
Why These Systems Fail After 15 or 20 Years
When an older system starts misbehaving, the causes are remarkably consistent:
- Corroded connections. Many older installs used pierce-style connectors that clamp through the cable jacket. They work at first, then moisture gets in and slowly eats the copper. This is the number one killer of aging systems.
- Splices that were never rated for burial. A twist connector and electrical tape under six inches of soil is a countdown timer, not a connection.
- Cut cables. New flower beds, a fence line, a regraded patch of lawn, an irrigation repair. Every shovel that touched that yard in 20 years had a chance to nick a cable nobody knew was there.
- Voltage drop from added fixtures. Systems grow over the years. Extra lights get tacked onto existing runs, and the fixtures at the far end slowly dim or flicker as the run gets overloaded.
- Water in fixtures. Gaskets dry out, glass cracks, and sockets corrode from the inside.
Notice what is not on that list: the buried cable itself. Direct burial cable is tough. In most aging systems the copper in the ground is fine. It is everything attached to it that gives up.
Diagnosing a System With Zero Context
So how do you fix something when there is no map, no labels, and nobody to ask? The temptation is to start digging where the dead lights are. That is the one move guaranteed to waste a day.
The system will tell you what is wrong if you test it methodically. Every measurement narrows the search. Guesswork digs holes, evidence digs one hole, in the right place.
Here is the process we used on that Essex County system, and the one we would use on any undocumented install:
- Start at the transformer. Identify every cable run leaving it, confirm which taps they are on, and measure what each run draws. Dead run with zero load? The break is somewhere downstream. Normal load but dark lights? Different story entirely.
- Isolate one run at a time. Disconnect everything, then bring runs back one by one. Problems that hide in a fully connected system stand out immediately in isolation.
- Measure voltage at the first and last fixture on each run. Healthy at the first, dead at the last? The fault lives between them, and each fixture along the way is a checkpoint.
- Tone trace the buried cable. A tone generator and probe let you follow the actual path of the cable through the yard without disturbing anything. This is how you discover the run that takes a detour nobody would ever guess.
- Dig only where the evidence points. By the time a shovel comes out, the search area should be a couple of feet, not a couple of flower beds.
On this system, the culprits were two corroded pierce connectors and one cable that had been sliced during a garden expansion years earlier, patched with tape, and quietly failing ever since. Total digging: two small holes, exactly where the measurements said to dig.
The Real Fix Was the Map
Here is the part that matters more than the repair. As we traced and tested that system, we labeled every run at the transformer, logged what each one feeds, recorded the load, and drew the actual cable paths onto a property map. Splice points got photographed before they were reburied in proper waterproof connections.
The homeowner now has the document the original install never came with. The next time something fails, whoever shows up will know in five minutes what took us a full visit to reconstruct. And if that next technician is us in another 20 years, we will be thanking ourselves.
The most valuable thing an installer leaves behind is not the lighting. It is the map that lets someone service it 20 years later without calling a company that no longer exists.This is how we handle every system we touch, indoors and out. Networks, smart home systems, landscape lighting, all of it gets documented like the next person to open the panel has zero context. Because one day, they will.
What to Ask For if You Are Getting Lighting Installed
If you are having landscape lighting installed anywhere in Windsor or Essex County, by us or anyone else, ask for these before the first trench is dug:
- An as-built wiring map showing where cable actually runs, not where the quote said it would run
- Labeled home runs at the transformer, so every cable can be identified without disconnecting anything
- A load schedule listing what each run feeds and what it draws
- Photos of every splice location before backfill
- Burial-rated waterproof connectors on every connection, no exceptions
A good installer will not flinch at any of this. And after go-live, the system should not be abandoned either. We stay on after handoff to fine-tune timers, adjust zones, and adapt the system to how you actually use your yard, because no install is truly finished on installation day.
If You Inherited a Mystery System
Maybe this post sounds familiar. The lighting came with the house, some of it works, and the transformer might as well be a locked box. You do not have to wait for the rest of it to go dark.
An assessment maps what you have, documents it properly, and catches the corroding connections before they take out a whole run. It is also the moment to consider an LED retrofit, which cuts the load so dramatically that runs suffering from voltage drop often come back to full brightness without a single new cable.
If you are in Windsor, LaSalle, Tecumseh, Amherstburg, or anywhere in Essex County and your landscape lighting is a mystery you inherited, email us at hello@neurodesk.io. We will bring the tone tracer, and you will finally get the map.