Thats the king lead from the dizzy to the coil - very important.I've got a spare one if you want it (its old though!), but you might be better just buying a new set of leads. These are good (bottom of page): http://www.vwspares.co.uk/g2electrical.phpIn the meantime try spraying it with WD40 to dry it out. Be careful as you can get a nasty shock off that lead.