If your garage door opener won’t open, and the motor unit lights blink 10 times, the problem is probably the safety sensors. The blinking opener lights mean that the safety sensors are likely blocked or out of alignment. Defective safety sensors or faulty sensor wiring also cause the opener lights to blink 10 times.
Here is some DIY troubleshooting advice to help to solve the problem.
1. Look for obstructions
First, look for an item blocking the door sensor and remove it.
2. Check sensor alignment
You may have bumped a sensor out of position. Each safety sensor has an indicator light. Check that the sending sensor’s yellow light is on and then check the green light on the receiving sensor. If the green light is off, realign the safety sensors until the green light turns on, and then try closing the door.
3. Check for error codes
If any sensor lights doesn’t come on, check the LED troubleshooting light on the motor unit for an error code. The control inside the motor unit flashes the troubleshooting LED a number of times to indicate the cause of a failure.
You may see one of these error codes related to the safety sensors on a common chain-drive garage door opener:
• 1 blink: Sensor wires are disconnected.
• 2 blinks: Sensor wires are shorted.
• 4 blinks: Sensor eyes are slightly misaligned.
A belt-drive garage door opener and some newer chain drive models flash the up and down arrows to display error codes. Here’s a list of error codes related to the sensors on these models:
• Up 1 blink, down 1 blink: Sensors are not installed or wires are broken
• Up 1 blink, down 2 blinks: Wires are shorted or reversed
• Up 1 blink, down 4 blinks: Misaligned or obstructed sensor
• Up 4 blinks, down 6 blinks: Sensors were temporarily obstructed or misaligned.
4. Check the wiring
If you see one of the first two error codes, check the wiring between your motor unit and the sensors for visible damage. You won’t be able to check all the wiring if it’s routed through the walls to the sensors. Check the wires that you can see and repair any broken or damaged wiring.
5. Check the connections
A loose wiring connection could prevent the garage door opener from closing the door, causing an error code. Check the safety sensor wiring connections on the motor unit. Reconnect any loose wires.
Make sure that you have the sensor wires connected to the motor unit correctly. You should see the white wires twisted together and inserted into the white terminal on the motor unit. The white wires with black stripes go into the gray terminal. Connect the wires correctly if you find them reversed.
6. Test your safety sensors directly at the motor unit
Test sending sensor first. Remove the sending safety sensor with the yellow light from its door rail bracket. Disconnect or cut the sensor wire about 1 foot from the end. The sensor wire has 2 strands. Separate the strands and strip 1/2-inch of insulation from the end of each strand. Disconnect the existing safety sensor wires from the motor unit. Connect the short, white wire strand to the white motor unit terminal. Connect the other wire strand to the gray terminal. Check the yellow light on the sending safety sensor. If the yellow light turns on, the sending sensor is okay. If the yellow light doesn’t turn on, you’ve confirmed that the safety sensors are defective. Here’s a link to a video that that will show you how to replace them.
Garage Door Opener Sensor Kit:
If the sending sensor is okay, test the receiving sensor. Remove the receiving sensor and cut the wire about 1 foot from the sensor end. Separate the sensor wire strands and strip 1/2-inch of insulation. Disconnect the sending sensor wires from the motor unit terminals and twist the white strands with black stripes together.
Repeat the process to connect the white sending and receiving sensor wire strands together. Connect the white wire strands to the white motor unit terminal and the white and black strands to the gray motor unit terminal. Hold the sensor eyes directly together and check the lights. If one or both of the lights fail to turn on, replace the safety sensors. If both lights turn on, press the remote button. If the door closes, the safety sensors are okay.
7. Fix the wiring.
If you’ve eliminated the sensors, the problem is a break in the wiring. Here’s a link to some replacement wiring that you can use to resolve the problem.
Replace the wiring and test the garage door.
We hope these DIY tips help you fix the problem.
If you need to have a Sears Technician fix your garage door opener, schedule service here: