BMW Repair: windscreen wiper fault, saloon series, park position

Question
i know you work with E30 3 series, but you may be able to help. My 1991 E36 318i 4 door saloon series UK Spec has a problem with the wipers. when they are turned on you cannot turn them off, only by turning off the ignition when they are in the park position will they stop.I have had a brand new wiper motor fitted and the problem is still there.Could it be the wiper control module which is under the facia. Also all relays are okay.Many thanks in advance.

Answer
Mark,
 I'm sorry for the late reply, I was sick all weekend.  

 Your problem sounds like an issue with the wiper switch.  You should be able to remove the steering column cover (fascia) and find the switch.  Replacement should be simple.  If you've replaced the wiper motor, this is the only other option to fix the problem.  Check all your grounds under th dash as well, it could be a grounding problem, however unlikely.

 Hope this helps,
 Josh