Why Is The Sensor On My Garage Door Not Working (SOLVED)

The garage door sensor is an important safety feature. There are a number of reasons why it can stop working, from dust on the lens to wire damage. If your garage door sensor isn’t working, you’re likely wondering what the reason is and how to fix it.

Always check the power supply if your garage door sensors aren’t working, as this is one of the main causes. The sensor will also stop working if there’s a wiring issue. Make sure the wires are connected correctly and there is no damage to them. Other reasons this may happen include faulty photo-eye sensors or a misaligned track.

The garage door may not stop if something gets in the way when the sensor isn’t working. When you notice your garage door sensor isn’t working, you should fix the problem asap. Read on as we discuss some of the most common reasons this happens and how you can fix it yourself.

What Do Garage Door Sensors Do?

Garage door sensors are a safety feature. They detect any obstruction that’s in the garage door’s path. This alerts the garage door opener to stop to avoid an accident.

In the early 1990s, it became mandatory for manufacturers to include garage door sensors with garage door openers. Garage doors are very heavy, as some exceed 300 lbs. If a person or animal got in the door’s path, it could cause a very severe injury.

This is also a very convenient feature for homeowners. If a tool or rake was placed too close to the door’s path by mistake, the door won’t damage it.

Common Reasons A Garage Door Sensor Stops Working

Garage door sensors have a green LED light. When this light is solid green, the sensor is working efficiently. If the green light is flickering or blinking, then the garage door sensor isn’t working.

Before assuming you have a problem with the sensor, check around it. If there is any dust, cobwebs, dirt, or debris caught on it, this can prevent it from working. You should also make sure the screws that secure the sensor haven’t become loose.

However, if the sensor is clean and the screws are fastened, the problem could be one of the following reasons.

Faulty Power Supply

The garage door sensor won’t work if it has a faulty power supply. You can detect a faulty power supply by looking at the sensor’s light. The green light will be off if the power supply is faulty.

Make sure your garage door opener is plugged into a working outlet. You should also check the circuit panel to make sure the breaker hasn’t tripped.

Faulty Supply

Faulty Photo-Eye Sensor Light

The photo-eye sensor problems are often the primary reason why a garage door isn’t working. If it’s damaged or broken, the photo-eye sensor won’t be able to send signals to the garage door opener.

You can detect a faulty photo-eye sensor by looking at the amber light. If this light is flickering, then you need to replace the sensor.

 Photo-Eye Sensor Light

Wire Damage

A loose or broken wire will prevent the garage door sensor from receiving power. You will be able to detect this because the sensor lights will be off.

In order to determine whether it’s a wiring problem or a faulty power supply, you should check to see if other items in the garage are receiving power.

Garage Wirings

Misaligned Track

A misaligned track causes a number of problems with the garage door. This is one of the biggest problems when it comes to a garage door’s performance. In most cases, you will not be able to open a garage door with a misaligned track.

One of the first ways to detect this is by a grinding sound when you open and close the door. You should not use a door with a misaligned track until it gets repaired. This is because there is a risk of the door falling off of the tracks.

Garage Door Track

How Do You Test A Garage Door Sensor?

It’s important to test your garage door sensor to make sure it’s working properly. This is something you can do with an everyday object that you plan on throwing in the trash, like an old box. When you close the door, place the object along the sensor’s path.

This is how you can tell whether or not they’re working. If the door stops and reverses, the sensors are working properly. However, if the door continues to close, they aren’t working.

How To Tell If A Garage Door Sensors Are Out Of Alignment?

Always check the lights to determine if the sensors are aligned. When the sensors are aligned, the LED light is green. However, if they’re misaligned, the light will be red. Another sign is a blinking or flashing light.

Luckily, this is a very easy fix. Inspect the area where the sensor sits on the bracket. Look for any loose screws and tighten them. Once everything is fastened securely, the light should turn green again.

How To Bypass Garage Door Sensors

Are the faulty sensors causing your garage door to stay open? You can bypass the sensors to close the garage door. This will give you peace of mind until you find the right solution for your problem.

Head over to the garage door opener’s control panel on the wall. Hold the down button until the door is all the way on the ground. Don’t release the button beforehand or else the door will release and travel back up.

Replacing Garage Door Sensors
Replacing Garage Door Sensors

What you need: safety glass, work gloves, wire cutters, pliers, step ladder, blue wire nuts

How To Replace Garage Door Sensors

  1. Turn off the power supply to the garage door opener.
  2. Unfasten the wing nut from the bracket to remove the sensor. Gently pull it off of the bracket.
  3. Repeat step 2 with the other sensor.
  4. Gently separate the new sensor’s control wires. Use the blue wire nut to connect the black-striped wire to the black-striped safety sensor wire. You will also need to connect the white wires the same way.
  5. Repeat step 4 with the other sensor.
  6. Place the new sensor on the bracket. Secure it in place with the wire nut.
  7. Repeat step 6 with the other sensor.
  8. Turn the power back on to the garage door opener.
  9. Align the safety sensors. You will be able to tell they’re aligned when the green LED light is on and not flashing.
  10. Test the safety sensor.

How To Check If Your Garage Door Sensors Are Working

After replacing your garage door sensors, you should always test them to make sure they’re working properly. It’s better to know right away if something needs to be realigned or repaired so you can address the issue.

As mentioned above, the most efficient way to test new garage door sensors is by placing a large box in the door’s path. Make sure the box is taller than the sensors. If you don’t have a box, you can use any item that’s the appropriate size that you won’t mind getting damaged.

If the garage door sensors have been installed correctly, the door will reverse. However, if the door crushes the box, the sensors were not installed properly.

What Is A Safety Reversing Sensor On A Garage Door?

The safety reversing sensor is used to detect obstructions in the garage door path. This is a mandatory safety feature that all garage doors must have.

So, which part of the garage door opener is the safety reversing sensor? This key component isn’t attached to the garage door opener on the ceiling. Instead, look towards the floor by the garage door. On each side of the door frame is a sensor.

This sensor is typically compact in a small to medium-sized black box. When everything is hooked up correctly, you’ll notice a green light on this box.

How To Troubleshoot The Safety Reversing Sensors

If you notice the safety reversing sensors aren’t working, you will need to fix them immediately. However, detecting the problem isn’t always obvious. Follow our troubleshooting steps to get to the bottom of the problem.

  1. Carefully remove the garage door sensor from the bracket that it’s installed on.
  2. Remove the wires from the wire nut, making sure to not cause damage.
  3. Strip the wires from both ends of the sensor. Twist matching colors together. Do this with both sensors.
  4. Disconnect the white and grey wire from the terminals that are currently connected at the back of the garage door opener.
  5. Insert the grey and white wires from the sensors into these terminals.
  6. Face the sensors towards each other. A light indicates that there is a problem with the wiring. If this is the case, move on to the next steps. No light means that you need to replace the sensors.
  7. Inspect the wiring from the safety sensors to your garage door opener.
  8. Make sure the wires are correctly connected. (ie: the white wire connected to the white terminal, the black wire connected to the black terminals, etc.)
  9. Give the wires a very gentle tug to make sure they are secured.
  10. Test the opener with the remote. If the garage door opens/closes, you have fixed the problem.

What To Do If Your Garage Door Sensors Still Aren’t Working

Some problems call for expert help. You may need to call a professional if you have checked out everything we’ve mentioned in today’s article and still can’t figure out what the problem is.

Keep in mind that hiring a professional will cost more because you have to factor in the cost of labor. The replacement sensors will cost roughly $80 to $100. Then you will need to factor in an additional cost for labor, which is usually around $180.

Tips On How To Keep Your Garage Door Sensors Working Great

You can keep your garage door sensors working great by inspecting them often and keeping them clean. When you keep an eye on the garage door opener and the tracks regularly, you’ll be able to detect problems early before they cause you a headache.

It’s also important to remember how low to the ground these sensors are. You should get in the habit of wiping them down to prevent dust and debris from building up. They can get dirty very easily, especially after storms.


The garage door sensors are essential for safety. If yours aren’t working, you will need to have them fixed right away. The main reasons this happens are damaged wires, improperly connected wires, and misaligned sensors. Most of these problems can be fixed DIY, but in some cases, you may need to replace the sensor.

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