Check the feed to the motor, it's a orange and blck pair. If you detach it from the motor and put a multi meeter across the connectors and switch the fan on you should get 12v. If you don't then check the fuse also try connecting your meeter between the orange wire and earth point and make sure you get 12v. If at the lead you get 12v then the motor has gone.
les
January 2011