Changing the auxiliary indicator (also known as a side marker light or corner light) on a Mercedes W201, or the Mercedes 190, can be a relatively simple procedure. Here are the general steps to guide you through the process:

Tools and Materials You May Need:

  • Replacement auxiliary indicator
  • Screwdriver or a socket set
  • Safety equipment (gloves, safety glasses)


  1. Safety Precautions:
    • Ensure the vehicle is parked safely, the engine is turned off, and the handbrake is engaged.
    • Wear safety gloves and glasses to protect your hands and eyes.
  2. Locate the Auxiliary Indicator:
    • Identify the location of the auxiliary indicator on your Mercedes W201. On most models, this is typically located on the front fender, near the wheel well.
  3. Access the Bulb Housing:
    • Depending on the specific design of your Mercedes 190, you may need to access the bulb housing from under the wheel well or by removing the inner fender liner. In some cases, you can access it directly from the engine bay.
  4. Remove the Bulb Housing:
    • Using a screwdriver or a socket set, carefully remove the screws or bolts securing the bulb housing in place.
  5. Disconnect the Wiring:
    • Gently disconnect the wiring harness connected to the auxiliary indicator. You may need to use a small flathead screwdriver to release any retaining clips.
  6. Remove the Old Indicator:
    • Carefully detach the old auxiliary indicator from the bulb housing. It may have clips or tabs that secure it in place.
  7. Install the New Indicator:
    • Align the new auxiliary indicator with the bulb housing and secure it by snapping it into place, making sure it fits securely.
  8. Reconnect the Wiring:
    • Reconnect the wiring harness to the new auxiliary indicator. Ensure it clicks or locks into place.
  9. Reattach the Bulb Housing:
    • Position the bulb housing back into place and secure it by reinserting and tightening the screws or bolts.
  10. Test the Indicator:
    • Turn on your vehicle’s lights to test the new auxiliary indicator. Make sure it functions correctly, including both the parking and turn signal functions.
  11. Adjust the Indicator Position:
    • If needed, adjust the new auxiliary indicator’s position to ensure it provides the proper angle and illumination.
  12. Final Inspection:
    • Carefully inspect the auxiliary indicator to ensure it is securely attached, properly aligned, and functions correctly.

Changing the auxiliary indicator on a Mercedes W201 is generally a straightforward procedure, but it’s important to follow these steps carefully to ensure proper installation and function. If you’re unsure about performing this task, or if your vehicle has specific features that make the process more complicated, consider seeking professional assistance.