Garage Door Safety Sensors | How to Tell Sending and Receiving Sensors Apart

Garage door safety reversing sensors protect people, pets, and vehicles from the path of a closing garage door. They work by projecting an invisible beam across the garage door opening (from the sending sensor to the receiving sensor). If anything interrupts the beam while the door is closing, the door automatically reverses to prevent contact.

Location: These sensors are mounted on both sides of the garage door opening, no higher than 6 inches (15 cm) above the floor. Each sensor has a small LED light to indicate power and proper alignment:

• Amber LED = sending sensor
• Green LED = receiving sensor

Note: Sensors may look different depending on the model. Your sensors may not exactly match the examples shown below.

Refer to the unique identifiers in the information below to determine which safety sensors you have.

041-0136 

• • 041-0136 Sensors (Introduced 2021)
  • Sending sensor: Square amber LED light
  • Receiving sensor: Square green LED light, sticker on the back
  • Both sensors: Hole for mounting bolt

41A5034

• Sending sensor: Small circular amber LED, flat lens
• Receiving sensor: Small circular green LED, convex/curved lens
• Tip: The lens is the small clear window that faces the other sensor. Make sure the sending sensor points directly at the receiving sensor.

41A4373A

• Sending and receiving sensors: Both have green LED lights
• Both sensors: Hole for mounting bolt
• Tip: These sensors and brackets are no longer available, but LED behavior can still help identify sending vs receiving.

Additional Tips 

• LED Color Check: Amber LED lights appear yellow-orange; green LED lights glow bright green. Check in a dim area to see clearly.
• Sensor Orientation: Ensure the sensors face each other. Misaligned sensors may cause the garage door to stop or reverse unexpectedly.
• Verify Installation: Both sensors should be 4–6 inches above the floor and mounted securely.
• Quick Troubleshoot: If the door won’t close, check that both sensors’ LEDs glow steadily. If one is off or blinking, it may be misaligned, obstructed, or disconnected.
• Wiring Note: Your sensors may look different, but the sending sensor is the one transmitting the beam, and the receiving sensor is the one receiving it.