Polarity of HELLA Rallye 4000 compact HIDs

[Anders]

Eh, they have a ballast so I figure it's electronic. Anyways, I have a pair of HELLA Rallye 4000 Compact HID lights. They didn't come with the manual and I don't know what the polarity of the blue and black wires equates to. I figure the black is probably ground, but if it isn't, and these things are finicky about polarity, I feared I would blow something

So . . . what is the polarity of the wire colors (one wire is blue and the other black)? And is there anything I should know about hooking them up?

Thanks