I would replace it mate. I just did mine and got it from burton power.
http://www.burtonpower.com/speedo-ca...d-fks2046.html

Quite an easy job, disconnect from the gearbox then remove the instrument binical screws and reach behind to feel the cable. It has like a little plastic ridge on it that you need to push in with a pair of pliers then pull it out through the bulkhead. Hope this helps