Insignia freezer shows E9; door alarm may sound even when door is closed; interior light may stay on.

Safety first: Unplug the freezer before removing the door switch or control panel trim.

Steps:

• Locate door switch: On Insignia uprights, the door switch is usually in the cabinet frame near the top; on some models it is integrated into the control housing.
• Check operation: Press the switch plunger by hand (for mechanical types). The interior light should turn on/off accordingly when the unit is powered. For magnetic types, ensure the door magnet is present and aligned.
• Test continuity: Remove the switch and test with a multimeter. It should open and close reliably when actuated. Replace if intermittent or stuck.
• Inspect wiring: Look for pinched or broken wires near the hinge area where the harness flexes.
• Replace switch: Install a new door switch or magnetic door sensor designed for your Insignia model. Ensure it sits flush and is firmly secured.
• Control board check: If a known-good switch is installed and wiring is intact but E9 remains, the main control board door input may be defective.

Tip: A faulty door switch can also cause temperature issues because the evaporator fan may shut off when the control thinks the door is open.