Thanks all!
Today I decided to take it off (AGAIN) and fix it myself!
The original problem was the slow speed wiper did not work, everything else did.
I bought a s/h unit off fleabay last year (never wanted to tackle the job though!) that the seller said worked perfectly........yeah right!
I took my original one off and exchanged it for the fleabay "perfect" one - joy oh joy the wipers worked in all speeds, slow, intermittant and fast..................but the headlamps didn't (and I even gave the guy +ve feedback!)
So, OK it at least told me that my original switch had a problem, and it was not the wiper motor at fault. 1 plus for me.
Then I searched for an original S4 NOS unit (not trusting any s/h unit again) but this is unobtanium - yes they all without exception (AFRA, OKP, Bertelsbeck, Classicalfa in fact most of the UK, German and US usual suspects etc) sell a new one for the S4, but believe me this unit, an aftermarket unit, is and looks completely different, wires are different, colour codes are different, switches are different and yours truly not having a degree in mechanical or electical engineering, I said thanks, but no thanks!
Today I took off my original one again (took lots of photos, step by step - might try and upload them one day on here for you guys and put them on a new thread)
I then took the s/h replacement one apart, as I thought if millions of springs pop out, I know what to expect on my original one when it came to doing that one! It is a tricky job, but actually not as bad as I thought, as it looked completely sealed. I mean just the wiper stalk part needed dismantling. It is actually very simple inside, only the clamps that hold it together are the tough part.
To be honest mine looked as good as the fleabay one, except the fleabay one was a little newer in feel, when you flick the wiper stalk down. There are no parts in the body that you can replace, all factory soldering etc, so i decided to just swop out the arms, and give mine a good clean inside.
Put the s/h arm into my original column switch, put it all back together, connected up the connections, put the battery earth back on and it WORKED, wipers, lights and indicators.
Job done, 300 euros saved - as i had taken it all off once before, this time it took me about 1/2 hour to remove and maybe 40 minutes to but back on (obviously when you put things back, you start cleaning contacts, greasing, WD40 etc.