Hi, you will find that the rubber seal that fits around the cluster has failed as this is a common fault on the mondeo. I had the same problem & contacted Ford customer services who replaced both seals on the rear clusters free of charge as i had the car from new, they explained that they were carrying the repair out as a good will gesture!!. if you have to pay for a replacement cluster you are looking at £100+. Hope this has been of some help ---- Good Luck
Kenny Jones
kenny jones
August 2007