td5 facelift trouble

hi just fitted the later style headlight cluster's to my disco ,looks the part and every thing is working except the headlight leveling system,wired as per the instructions but nothing happening ,do all the new headlight clusters have the levelling system? Checked lights at night and they look spot on for height and the car has SLS to compensate when towing the caravan but i hate having a switch on the dash that does nothing any help appreciated!!!!!!thanks

When I did my lights I did not bother with the levelling system as I was not sure how to wire it at the time, meant to investigate further but 3½ years later I am still meaning to!