This sounds very familiar ...... take a look at this!!!
http://www.lancia.myzen.co.uk/forum/index.php?topic=8848.0There was a lot of clicking going on but no action!!! The nodding donkey relay (the left hand one) was not doing its duty!! The electro magnet bit was working, hence lovely solid clicks, but the nodding donkey mechanism was not engaging with the 4 tooth sprocket. The sprocket was not turning through a full 90 occasionally and this means the whole mechanism becomes ceases to function. A little light lubrication may do the trick if you are lucky, it did not work for me, but it is worth a try!!!
Good luck, please keep us informed as to how you are getting on.
Andy