If a bulb burns out
Modifications or repairs to the electrical system carried out incorrectly and without bearing the features of the system in mind can cause malfunctions with the risk of fire.
You should have the bulbs replaced at a Fiat Dealership. Always check the height of the headlight beam after changing a bulb.

Only touch the metal part when handling halogen bulbs. If the transparent bulb is touched it reduces the intensity of the light emitted and can also reduce the life of the bulb. If you touch the bulb accidentally, rub it with a cloth moistened with alcohol and leave it to dry.
Halogen bulbs contain pressurized gas which, if broken, may cause small fragments of glass to be projected outwards.
Test yourself
A quick Fiat Doblo quiz: every answer comes with an explanation and a link to the manual page.