How did u check the cable worked?! Easiest way is jack the back end up and put it into gear and you'll see if its turning or not,(obvoiusly disconnecting it out the back of the clocks so u can see if its turning or not!) or remove the drive bit out the box and turn it by hand, or try another set of clocks!!

Piece of piss 2 change thou mate, easiest way is take the drive bit that goes into the box, its just a torq bit holding it in and a small plate then just pulls out (might need some gentle persuasion) then theres a circlip holding the cable inplace take it off and voila fit new 1!!!

U might find thou that its just come out of place in that end, mine stoped working after i changed my clocks for no reason, went to a parts place who got me the wrong one in the end and said it was the only 1 they lsited for a cossie

SO basically i pulled the cable (middle bit that drives the clocks) as far out as i could and plugged it back into the drive bit, turned it by hand and it was working again!!!