intermittent fault,ford focus 2002

Its a ground problem. Check ground between battery and body as well as ground to engine. Remove wires clean thoroughly maybe use some fine sandpaper to ensure good contact. Then the speedo or rather instrument ground may also be loose. First check ecu ground then actual cluster ground. If work has been done on the car prior to problem check the area work was carried out to see for loos or kinked cable. Hope this helps.

thanks i'll try that i was going to change the speedo sensor