Both of my 93 RR vogue classic front seats have u.s mechanisms. Anyone else had this problem and any clues? I've heard meths is the answer but I've tried drinking that and they still don't move even if everything else does...

The horn on my 93 classic won't work. I've checked the horn itself and I've looked inside the switch. The contacts shut ok when I bridge across the pins but one of the two pins that are the horn has no feed and I've no diagram to show me what's what. Anyone got a diagram or is a wheeze on these...