upgrading of headlights on c 2.0l petrol c5?

You should rewire your uprated bulbs to a relay to take the extra amps drawn by the higher wattage of the lamps. The original wiring will be used to switch the relay when the headlights are used. You will need two relays, one for the dipped and one for the main. Uprated fuses also need to be put between the relay and the bulbs for extra safety against a short.

Homer
July 2010