> When I push it down to that lowest
>position, the wipers don't run and nothing else seems to happen
>either.  What is it supposed to do?  Am I turning someone's wipers on
>and off in South Africa?

My '73 is the same. I always thought it could be for intermittent wipers
that my bus, being a cheapo no-frills 1600 version, didn't get. I know VW
did that with the reversing lights. My bus has the lights, just with no
bulbs or holders inside. When I bought it I thought there must just be a
blown fuse or duff wire or something until I read somewhere that they were
an option. In reality that meant you had to stump up more cash, on top of
what you were already paying for your new bus, just for VW to connect them up. 
I've never bothered to examine the wiper switch but it may turn out that by
just adding a few extra wires in the right places you end up with
intermittent wipers for free. Has anyone's bus got a wiper switch that does
something when you move it down?