I have a 1994 BMW 318i (E36) and it is now past 200,000km in total mileage.
One of the recurring problems is perhaps to do with the electrics; the wipers seemingly have a mind of their own, continuing on a constant wipe cycle even when the “once only” step is selected.
The wipers sometimes stop on their own accord, but far more often only stop when the car is switched off.
How can this be tackled?
Reply: I think your problem is with the wiper module and the only solution is to replace it.