I almost left my zed at home last week when we drove to yorkshire because the wipers had started to behave erratically, parking in random places & not turning off!
I managed to get the wipers off with a tawdry puller from ebay that I ended up modifying so it worked
Wiper motor cover off
Carefully balanced on my motorbike for cleaning
Wiper motor on my bench (along with some metal monkey tips) for cleaning
This is the bit that causes the aggro, it gets grease on the conductive tracks causing the park signal to become corrupted, cleaned it up & back on the car in a jiffy working like a windscreen wiper should!
Regards

I managed to get the wipers off with a tawdry puller from ebay that I ended up modifying so it worked

Wiper motor cover off

Carefully balanced on my motorbike for cleaning

Wiper motor on my bench (along with some metal monkey tips) for cleaning

This is the bit that causes the aggro, it gets grease on the conductive tracks causing the park signal to become corrupted, cleaned it up & back on the car in a jiffy working like a windscreen wiper should!
Regards