Window Switch W166 for Mercedes-Benz

OE spec power window switch, engineered for Mercedes Benz ML and GLE W166. Restores factory window and mirror control after worn buttons, broken contacts or liquid damage. Sold per piece, select position, driver master, passenger front, rear left, rear right, and match the connector layout.

What this is / isn’t:
Included: 1× electric window switch module, position specific, with connector sockets.

Important: Match by VIN and options. Driver master switches differ from passenger and rear units. Trims with power fold or memory mirrors can use a different part and icon set. Illumination and locking child switch vary by year and package. Always confirm by OE number.

Key Features:

• Exact fitment: Factory mounting tabs and plug interface for a no mod install.

• Reliable contacts: OE grade tactile domes and tracks for consistent switching.

• Correct logic and lighting: Works with the door control module, backlit where applicable.

• Durable housing: Impact resistant plastics that handle daily use.

• Clean look: Factory correct icons and finish to match the interior trim.

Compatibility:

• ML Class W166 2012 to 2015, all body styles and trims.

• GLE Class W166 2015 to 2019, SUV models.
  Drivetrain and engine do not affect the switch, equipment level and year do. Verify by VIN.

Options, positions and functions:

• Driver side master → window controls for all doors, mirror adjust, mirror fold on equipped vehicles, window lock.

• Front passenger side → single window control, some trims include mirror adjust if configured.

• Rear left or right → single window control with illumination where fitted.

• With or without mirror fold → choose the version that matches your mirrors and door module.

Typical OE reference families, guide only:
A166 905 … , A166 545 … , variations by side, year, illumination and mirror functions.
Always order by the exact OE part number on your vehicle or confirm via VIN.

When to replace the switch:

• Window works from another door but not from the local switch.

• Sticky, sunken or cracked buttons, intermittent response.

• Backlight inoperative on the switch though fuses are fine.

• Visible corrosion after water ingress or spilled drinks.

Installation notes, pro tips:

• Disconnect the battery if required by service info, then remove the trim carefully to avoid broken tabs.

• Release the locking tang on the connector, do not pull on the wiring.

• Test all windows, mirror adjust and fold before refitting the door card.

• If a window still does not respond, check the door module, regulator and fuses.

What’s included, not included:
✅ 1× Window switch module, specify side and function set
❌ Door trim panel, wiring loom, separate mirror switch if applicable, clips, fasteners or fuses

Q&A
Q1: Will a driver master switch fit the passenger side?
No, driver, passenger and rear switches use different layouts and electronics. Order by side and function.
Q2: Do I need coding after replacement?
Most W166 switches are plug and play. Some trims may require a basic adaptation through the door module.
Q3: My new switch does not fold the mirrors, why?
You may need the version with fold function, or your vehicle is not equipped with power fold mirrors. Match by OE number.
Q4: Will this fit the GLE Coupe C292?
C292 uses related components but part numbers can differ. Match by VIN to confirm.

Why choose TOParts:
OE grade electrical parts for Mercedes Benz with precise fitment, correct pinout and long term reliability, trusted by panel shops and independent Mercedes specialists across South Africa.