Thanks for reply. I read somewhere on another site,i dont know which,sombody was doing the same thing,and had a reply to change it all including the speedo assembaly,and it may need matching. I still dont know how or why this would be needed,but as i had seen an ECU with all the stuff for sale on Ebay for £50 i thought there was something that sombody else knew about changing them with the speedo. Just waiting for it all to arrive.