my Volkswagen Tiguan First Generation (2007-2018) interior lights stay on when the car is off

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect and Replace Door Switches

• Locate the door switch on each door.
• Remove the door panel if necessary to access the switch.
• Disconnect the wiring harness from the switch.
• Test the switch with a multimeter to ensure it opens and closes properly.
• If faulty, replace the switch with a new OEM part.
• Reassemble the door panel and reconnect the battery.

3. Check and Replace Fuses

• Locate the fuse box, typically found under the dashboard or in the engine compartment.
• Identify the fuse related to the interior lighting (refer to the owner's manual).
• Remove the fuse and check for continuity using a multimeter.
• If the fuse is blown, replace it with one of the same rating (usually 10A or 15A).
• Close the fuse box and reconnect the battery.

4. Test Light Switch Operation

• Turn the ignition on and check the functionality of the light switch.
• Cycle through the settings: off, door, and on.
• Ensure lights respond correctly to the switch positions.
• If the switch is faulty, remove it and replace it with a new unit.

5. Inspect Wiring

• Visually inspect the wiring harness for any signs of wear, fraying, or corrosion.
• If damage is found, repair or replace the affected wiring.
• Ensure all connectors are secure and free of corrosion.