wipers not working

wondering if anyone can help.
girlfriend has got a 2005 mini convertible wipers working on intermitent speed then on constant sweep stays intermitent then on fast sweep onlys goes at slow speed sweep.
Seems that secondry wiper relay is not receiving switched ground anyone had the same fault???

That could be a faulty speed sensor. When the car is stopped the wipers automatically drop down one setting. I'm not sure where the sensor is on MINI though.