you need to figure out what type of speedometer you have first e.g 2000 model, elx?, sporting?. it may be as simple as the lead under the bonnet is loose which can be sorted by checking the connection, or like mine you need to buy a replacement. cost £30 from breakers yard and simply screws in. v v easy!!
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.