Why is my Arm-A-Door is not arming when I turn the key ? February 12, 2026 20:28 Updated Catalog FAQs Why is my Arm-A-Door is not arming when I turn the key ? Answer Possible Causes No power is reaching the unit. The unit is not engaging the arm function. The subassembly is damaged or failed. Solutions Verify power is present. Install fresh 9-volt batteries and reset the unit. Confirm the key cylinder engages the microswitch and that the microswitch functions properly. Replace the subassembly if it is defective. Applies To ARM-A-DOR Related to Arm-A-Dor Related articles How do I reset my Arm-A-Door unit? ARM A DOR FAQ's ARM-A-Dor Installation Instructions Why does the Arm-A-Dor alarm sounds when I arm my unit and the door in the locked position? Why is my Arm-A-Door is not arming when I push on it?