Fixing the headlight motors...

If you notice a buzzing sound coming from the front of your fortwo when the lights are on, it is likely to be the motors for the automatic adjustors.

It may be possible to stop the buzzing by turning the height adjuster by one level, but this is not ideal. As the motor adjusts the projection angle of the light, it moves a potentiometer that tells the circuit it is at the correct angle. Over time, this potentiometer builds up with dirt and breaks the contact. The motor will not stop as a result. If uncorrected, this may burn out the motor.

In order to fix this, remove the offending cluster from the car and remove all the bulbs from it.

You need to remove the clear lens cover but the clips (see below) that hold it in place become very brittle with age. You can try placing the unit in a warm place (e.g. airing cupboard) to make the plastic more pliable.

Carefully free all the clips and remove the cover from the rest of the unit.