Fabia cutting out whilst driving and no fan..?

Dear All

  First post - have read a few threads over last few months but perplexed enough about my latest problems to join up and ask the pro's..!

I have the 1.4 mpi 8v petrol 2003 fabia. a year ago i had some problems that i traced to the thermostatic sensor, replaced it and all good for about a year. - Have read many threads on here about this item. 

However, recently I went through an automated car wash and couldnt start the car afterwards - had to push it down the road and waited half hour for it to dry out before it would start. It was ok for about a day until it suddenly started to cut out intermittently whilst driving. Noticed that the fan has also stopped coming on - not sure how its related though. 

So I checked the fan was working by short circuit and it was ok so then replaced the switch/sensor in the rad as thats what the 'Haynes' manual said would be the problem. Fan still not coming on...?? anyway the car is not running right at all and worried that it could just cut out again. at the moment i cannot seem to replicate the fault but find it strange that the temp dial does not go off the scale..i.e engine overheating issue....as the fan is not coming on when stationery. The temp dial only ever gets up to half way....however, it was cutting out whilst idling when it first occured a couple weeks ago. - needless to say havnt driven it for a while and cant work out whats going on..! and desperate to avoid garages as can do most work myself.....even bought a VAG diagnostics tool - no codes....(..??

Any ideas peoples?

Much appreciated

Adam