hi, i'm hoping someone can help with a problem i have on my 1995 e200 w124 estate. normally the windscreen wiper works as it should but on a couple of of occasions i have been unable to turn them off. i've tried switching through all the available positions and then back to the off position but to no avail, they just keep going. by the time i get home and am able to investigate further they have started to work as they should again. if anyone could help with this it would be very much appreciated. thanks in advance, rod.