I fixed the wipers - it fixed any intermittent problems too (sticking). Most of what I've read on the forums are red herrings. the problem was a dry joint on the circuit board attatched to the motor. I suspect it would be the same for everybodys wiper problems though the brushes are low too and will need replcing soon.
There is NO value in removing the grease from the contacts on the rotating plate. Or using WD forty as a hopeful cure. I only discovered the dry joint by accident having given up hope but remaining nosey and trying to open the closed side of the circuit board, the business end. As I tried to lift the board I noticed it was lifting, off a contact, one of several pin contacts. ten seconds with a soldering Iron dabbing each of the main contacts, thankfully, cured the system.
I stripped the housings to get to the motor then inspected the motor. I attached a 12 volt Batt to the motor which did it's thing. So i new it was in the control system, the board. I'd already checked the relays (unecesserily), and other stated red herrings. All the wiper mechanics has to be lifted to get to the motor. Don't do what I did and forget to put the motor housing and water deflector back when you re assemble, I had to restrip the whole damn thing.
It was a lovely feeling seeing the motor work again... and properly. By the way, I blew through all the washer hoses and cleaned all the joints - fiddly - there's a pressure valve which lets water out if theres a blockage. Someone had tried to fix it closed with gasket cement because the system was blocked perhaps and water not getting to the blades. I will by a replacement, the size of a farthing, or get a three way splitter. A blocked hose or valve means water is leaking into the well everytime you use the washers, I suspect every GTV on the road is doing this. Worth a look.
Now for the exhaust. I've decided not to replace all the boxes but make a pipe striaght to the back boxes from the cat, it will be noisey but cheap, and no noisier than how it is now, completely seperate by corrosion from the rear two boxes. I woder why Alfa didn't try and get a few more boxes under there!!!!!