Retrofitting Interior Light Delay Unit

This mod will allow you to fit a Dimmer unit to your interior lights. This uses genuine BMW components.

Parts

Source your Interior light delay relay (PN. 61311373974 and 61311380233)

Prodecure

Remove the lower steering column cover (3 plastic clips) Remove the plastic trim that covers the driver’s side speaker in the foot well. This requires removal of the single screw at the bottom left of the speaker grill. The panel can then be pulled free of the door-seal that holds it in at the bottom. Remove the speaker – should be only three screws left as the fourth also held the plastic trim that you’ve already removed. Undo the two screws just below the speaker void – see photo below:

Reach down inside the speaker void and withdraw the central locking relay, mounted on a triangular metal plate. You now have access to the interior light relay socket:

Plug the light relay into this plug. (It only goes one way round), then attach the light relay to the central lock relay with a wire tie.

Now you need to swap these 2 wires.

Disconnect the brown/purple wire from the door switch, and plug it into the brown/purple socket (marked below). Then plug the brown/yellow connector into the door switch. (also marked in the picture below).

You also need to join together the brown/green wire and the brown/yellow. Cut the brown/green wire about 2 inches above the plug and join the plug end to the brown/yellow wire.

If using the OE BMW unit with 6 pins, you have to cut the brown/green wire a couple of inches from the socket and splice it to the brown/yellow wire. This is because if the delay unit wasn't factory fitted, the door handle switch is not fitted.

Your light delay relay is now installed.

Refit the central locking module, then the speaker and kick panel.

  LEGAL DISCLAIMER: I am not responsible for any problems that may arise following this procedure. Any work you do is at your own risk.