Could be the capacitor has failed. It'll look SOMETHING like this:
http://www.ukanfixit.co.uk/content/hotpoint-ariston-indesit-motor-start-capacitor-7uf-c00199432-or-1703644
It may be fitted to to the motor, standing off on a bracket or it may be on the baseplate somewhere
Check the model number of your drier and make sure you get the correct part.
X
May 2015