How to Install an Auto-Dimming Mirror on the Renault Laguna III

To install an auto-dimming mirror (electrochromatic: available on AliExpress with code 1005007387014612 for £71.39 with free delivery) on the Renault Laguna III, the first step is to remove the old mirror. The procedure is delicate: carefully slide off the plastic covers around the mirror (the clips are fragile), then detach the mirror from the mount fixed to the windscreen.

Do not force it: move it left and right until it comes off, or slide it upwards. Be careful not to break the windscreen.

The crucial point is the wiring. On many Laguna IIIs (especially phase 2), the connector for the electrochromatic mirror may not be present.

Under the cover of the rain/light sensor, some users have found only connectors for the rain sensor and humidity sensor, without the grey connector for the mirror. However, other users report that the pre-wiring is present and that you just need to connect the grey connector.

Before buying the mirror, remove the cover and check if there is a free connector. If the connector is not there, you need to find a switched live (positive after ignition), not a permanent positive, otherwise the mirror would always be powered.

One user found the correct power supply in the ceiling light near the mirror/sensor group: it is active with the engine on and cuts off shortly after turning off and locking the car. For the connection, the video suggests red = +12V and black = ground, but check with a multimeter.