Hi Sjoroveren
If you contact Dick Lai in Shanghai,
dicklai@wisperbike.com he well send you the wiring diagram it is very easy to follow, Dick will also be able to help with any other technical details.
I don't want to pass the buck but but Dick has dealt with most of the problems with these bikes from Germany.
I have told Dick you will contact him and asked him to make you a priority.
Best regards David