On the cross member in front of the belts you will see a small black box called the daytime running light module. If you provide ground to grey wire with black tracer it will turn the daytime lights off as it thinks your parking brake is on.
I do believe if you unplug it the headlights will not work. I think in the USA they plug some sort of jumper into that plug. You will have to check with the local dealer. Or some of the US guys might be able to see what they have plugged into that wire