Originally Posted by NJspeed69

Its done! The HIDs look awesome, unfortunately its still daylight out. The only problem I had was figuring which wire was ground and which was power, on the stock harness. Finally I had to take a guess. I actually took two seperate trips to Home Depot to buy a voltometer, only both times they gave no reading when I put it into the headlight plug with the headlights switched on. Strange.

The really wierd thing is on the stock headlight harness, there is two black wires going to one side of the plug, and one black wire going to the other. Makes you wonder why they couldn't color code it, what a pain. So hmm the question is which is ground and which is power?

Finally I was like this is ridiculous, the one with two wires going to it has to be the power, so I took a leap of faith and plugged it in on one side, and it worked!

SO FOR FUTURE REFERENCE, IF YOU INSTALL HIDS, DONT BUY A VOLTOMETER.
-LOOK AT THE STOCK HARNESS.
-THE SIDE WITH TWO WIRES IS THE POSITIVE.
I'm sure at some point along the line, someone will do a search for HID and actually use this information.

BUTTT, I can't figure out why it's like that.

Could the wiring perhaps be a leftover from the Mercedes SLK? An H7 bulb can actually be used for both high and low beams, but our cars aren't set up like that.. makes you wonder why they used the H7 at all. Perhaps the SLK was set up to use it for high and low, and the second wire feeds in addittional current when the high beams are turned on. This also leads me to think our cars might possibly be able to handle 100w bulbs, for those of you who want to get brighter headlights without going HID. I don't care enough to actually look up how the SLK is set up, but I think this is a good hunch.

Oh yeah I also upgraded the stock headlight fuses to 20 amps, which my kit recommend. As a side note, although HIDs run at 35w, they actually pull far more than that when first fired up.. then it slowly drops down to 35w.

Anyway I'll have pics up by this weekend. The yellow fogs with the purple HIDs looks great in the day.. can't wait to see it all together tonight. I'll finally be able to see. It's gonna be an incredible improvement over the crap blue bulbs i had.