Done and it's definitely the Gook!!
What I didn't figure before I got the switch out is that the rotation of the switch transmits down the stalk to the body of the switch @ the steering column. Only the intermittent switch has it's contact in the stalk.
Remove wiper switch (see my other post) only 4 screws
No need to remove the s-wheel)
Go indoors. (here I recommend you send SWMBO to the shops so she won't complain about the smell of oil)
Open the switch by releasing the 4 lugs (2 shown with arrows) and gently opening the switch.
Clean the Gook with a toothbrush ( I used an old one
) and WD40.
The two white plastic sliders lift out of the switch body for individual attention.
Next if I had some I would put a
light smear of vaseline (/electrical grease) on the contacts.
Push the switch back together.
Re-fit the switch. Now works like a dream.
p.s. Sorry but I forgot to take the after photo !!