First and very important information:
Due to our very very weak multifunction switch connector a relay harness is highly recommended for every hid kit installation.
You don't wanna have it looking like this:
more info here
Once you bought a relay harness you may have noticed that they are often connected for "9004" what is completely different to our "9007" system.
That will give you a totally strange light output: high beam is low beam, high beam indicator will glow in low beam and something else. Short said: It will not work how you expected.
So here is a diagram how to connect the harness correctly that your low beams work very fine and also the solenoid in the projectors will flip the deflector when you switch to highbeam - and the projectors will still light up.
(w/o a diode you would not have the right effect cause the low beam turns off when you switch to high beam. That would cause that also the hids turn off - and therefor we have now the diode. The highbeam current flows over the diode to the relay to turn the hids on. That will give you also the headlamp flasher function! In the other direction the diode avoids the current from the low beam from flowing to the bi-xenon solenoids!)
Mostly you have to remove all wires from the plug and rearrange.
The contacts are hold by a barbed hook and absolutely easy to remove with a very small screw driver.
Also you will mostly need a diode (a very simple diode from radioshack) for the correct high beam!
This wiring diagram is found on the internet - but i had to check and correct it.
(So it is half my work - but the most important half...)
You can trust my diagram - i am electronic technician and know what i am talking about...
Colors can vary - mostly ground will be brown (how it has to be in cars).
You see the 9007 plug in the picture:
You can see there 2 black wires = 2 x ground! The white and one black are going to the relais. The other black and blue are going to the high beam solenoid!
One thing more for the relay:
It is absolutely equal if ground or 12V goes to the 85 or 86 - polarisation is not stringent.
Same for the 30 and 87.
You only have to look that 85 & 86 = electromagnet side and 30 & 87 = switched side!
You may have seen other solutions for the "high is low and low is high" problem (like: just change blue and white) - but they solve only half of the problem and will not work right with bi-xenon projectors!!!!