Hi Alan, we used to do all our dealers alfas (until our leckie left to work for them) and they were always faulty wiring to tailgate-but you've discounted this. I asked today & he said the only other 'usual' place is if yours has got powerwash-the wiring goes at the pump behind the bumper,if yours has pw perhaps its when the customer uses it? dark mornings? hth ian(n)