Up Arrow LED Off, Down Arrow LED Flashing
LiftMaster
Shorted Travel Limit Circuit
LiftMaster opener will not run; DOWN arrow LED flashes and UP arrow LED is OFF.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Shorted limit switch, crushed limit harness, moisture intrusion on limit contacts, misaligned limit actuator causing continuous contact
How to Fix / Troubleshooting
Safety: Unplug the opener before working on wiring or switches.
- Visual inspection: Remove the opener cover and inspect the limit switch assembly and wiring harness for crushed insulation, exposed copper, or signs of water damage.
- Check actuator position: Ensure the limit actuator is not jammed against the switch, causing a constant closed circuit.
- Isolate the fault: If possible, disconnect the limit switch harness from the logic board and check if the LED pattern changes when power is restored. If it does, the limit assembly is likely shorted.
- Dry and clean: If moisture is present, dry the area thoroughly and clean contacts with electrical contact cleaner.
- Replace damaged parts: Install a new limit switch assembly or harness if any damage or burning is visible.
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Repair Difficulty
Medium
3/5
Required Part
Limit Switch Assembly / Harness
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