Wiring Question on roof lights

I got my hummer h2 with the XTC bar lights. 110 watts total on 4 lights , i dont have the wiring harness and they want 250.00 dollars for it which i find very expensive , so i'am going to make my harness. The lights have 2 wires one black and one white is the black ground and the white power . Anybody that can answer me please let me know . RKI

DC doesn't really matter.... but black is usually always ground in a DC circuit.

I agree with muddydawg75, black should be ground in the GM wiring.  However, black is always hot in other applications.  I would consult Chiltons or the dealership to be sure because the color codes are variable in cars.  White would be neutral in other applications. 

thank you i let you know what happen. RKI

You should be fine.... the lights are not gonna matter... Just run a ground to the black throughout.... run a red wire to the line side of the switch and a red from the load side and to the white wire and you will be fine... if you want to get creative use two switches and run outsides and insides...