Yeah original harness should be there, the new one usually just plugs in to the factory harness then to the two boxes, one per side.

Now with a cherokee the oem was a sealed headlight unit, meaning the plug plugged into the back of the headlight, no bulb. You may have to just look at it and see if the factory harness can just plug into the oem type bulb.

Basically just look at it and see what you have and go from there. You can post pics and we can help you. My experience with HIDs is with my wife's Grand Cherokee WK. So I may be off on some of the details.