The Bright Ideas Blog

Design inspiration and outdoor lighting tips and advice for homeowners

Troubleshooting Low-Voltage Landscape Transformer & LED Systems

It can be frustrating when your landscape lights stop working for no apparent reason. When this happens, its been my experience that the best place to start is troubleshooting your low-voltage landscape transformer.

Before we get into this, I should first mention that its always a smart decision to get a professional involved if you don't feel confident working around electricity. 

Troubleshooting Your Transformer

If your landscape lights are struggling, the best place to start is at the transformer

(The "silver" box that powers your low voltage landscape lighting).


We're going to focus on a very specific point about troubleshooting low-voltage landscape transformer: Restoring lost power. You'll need to locate your transformer to get started. 

Here are a few places to check if you aren't sure where your transformer is located. 

  • Check the exterior of your home. Since the transformer needs  a 120V power source, it will very likely be located near an exterior outlet. 
  • The Garage is another great place to check. Be sure to check behind things, the garage tends to hide/obscure transformers behind things. 
  • If your transformer isn't located near an exterior outlet or in the garage, check the shed in the back yard. If 110v power has been ran out to the shed, its likely the transformer could have been installed there. 

Once you've located your transformer, the first thing you'll want to do is establish weather or not your transformer has power.

One of the most common problems we come across with 12V outdoor lighting systems is a lack of power on the 120V side. 

If the transformer isn't receiving power, it can't redistribute 12V power out into the landscape to the lights. 

Determining Power

How do you figure out if the transformer is getting power? Your transformer will be plugged into an outlet. If the outlet doesn't have power, the transformer won't have power either. 


To test your outlet, plug in an electrical device and see if it works. A mobile phone charger will be great for this. After you plug the charger into the outlet, plug the charging cord into your phone.

If your phone begins charging, then you know that the problem is  somewhere in your lighting system (Click here to learn more about 12V side of your transformer). If your phone doesn't begin charging, you'll need to restore power to the outlet. 

Restoring Power to Outlet

If your outlet doesn't have power, you'll want to look closely to see what kind of outlet you are dealing with.  

There are two different kinds of outlets: the standard kind, and the GFCI kind. What's the difference? 

GFCI stands for Ground Fault Circuit Interrupter. Unlike the your standard outlet, a GFCI senses if any sort of current runs through the ground wire (if there is a short of fault) and turn the outlet off. 

If your GFCI is shut off, try pressing in the reset button to see if it restores power. Often, there is a small green indicator light that will illuminate after the GFCI has successfully been reset. 


My GFCI Won't Reset 

If your GFCI reset button doesn't want to reset, then there is likely also a tripped breaker switch in your home's breaker panel that will need to be reset to restore power to the GFCI. If a GFCI doesn't have power, it won't reset.

Go to your breaker panel and try to locate the flipped breaker switch. Look closely, sometimes a breaker switch won't flip all the way after its been tripped.

Be sure to check all your breaker panels. If you are able to locate your tripped breaker switch and reset it, your GFCI should reset. 

If you've managed to restore power to the outlet for your transformer, open your transformer up and hit your control timer's on switch. If you hear the low hum of your transformer turning on, you know you're good to go. 

But just in case, be sure to also go look and see if your lights are on. 

My Standard Outlet Doesn't Have Power

As frustrating as this can be, if you are dealing with standard outlet without power, you are still very likely dealing with a GFCI issue. Confused? I don't blame you. If there is a tripped GFCI on the same circuit as your standard outlet, neither the GFCI or the outlet will have power.


How do you find the tripped GFCI? You'll have to play detective. Here are a few places GFCIs are often found in the home. 

  • Places with an outlet near water. Check in your bathrooms and next to the kitchen sink.
  • In the garage next to the work bench. There always seems to be a GFCI in the garage. 
  • In the laundry room. 
  • Under the kitchen sink. 

In addition to these common places, remember that GFCIs can also be found in odd places. For instance, I once spent an hour and a half trying to help a client locate a tripped GFCI inside their home. Turned out their tripped GFCI was at the very back of their main level coat closet. There was no way they could have known.

If you get frustrated trying to locate the tripped GFCI, just remember, look in the places you wouldn't normally think to look. 

If you manage to find the tripped GFCI, reset it and go back to your standard outlet to test it for power. If you have power, you are all good to go.

Landscape Lighting Makes All The Difference


At Landscape Lighting Pro of Utah, the art of outdoor illumination is a real passion we work to perfect. Designing elegantly bespoke landscape lighting systems is simply all we do. For over 15 years, our award winning team of designers and craftsmen have striven to bring the best outdoor lighting experience possible to people's homes and businesses across the Wasatch Front & beyond. 

Located in Midvale, Landscape Lighting Pro of Utah installs, maintains, and repairs lighting systems throughout Utah's residential areas, including Salt Lake City, Park City, Draper, Davis, and Utah Counties.

If you have an upcoming project you'd like help with, call (801)440-7647 for more information, schedule a free consultation, or feel free to simply fill out a contact form on our website, Free Landscape Lighting Design Guide

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