my Ford Mustang S650 (2024-Present) interior lights won't turn off, what’s wrong?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent any electrical shorts during repairs.

Tools Required:

• Multimeter
• Screwdrivers (Phillips and flathead)
• Torque wrench
• OBD-II scanner

2. Inspect and Replace Door Ajar Switches

• Sub-steps:
  1. Open each door and locate the door ajar switch (usually located in the door frame).
  2. Remove the switch using a screwdriver if it appears damaged or non-responsive.
  3. Use a multimeter to test the continuity of the switch; replace if faulty.
  4. Install the new switch, ensuring it is properly seated and secured.

3. Check and Repair Lighting Control Module

• Sub-steps:
  1. Locate the interior lighting control module, typically found under the dashboard or near the fuse box.
  2. Disconnect the wiring harness from the module.
  3. Inspect the module for signs of damage or corrosion.
  4. If defective, replace the module with a new one, reconnect the wiring harness, and secure it in place.

4. Test the System

• Sub-steps:
  1. Reconnect the vehicle battery.
  2. Turn on the ignition and test the interior lights by opening and closing the doors.
  3. Verify that the lights turn off as expected after closing the doors.