if yours is working and you'd like it NOT to, I posted the fuse to pull on the US forum. if it's not working and you WANT it to, it's way more likely you need to do the battery reset dance detailed in several posts. if you really do need to get to the switch, I'm sure we can dig up the answer.
You have to take the seat out, tip it upside down and then you can just about access it...I had exactly the same problem, nothing really needed fixing per se, just fiddling and verifying connections etc. I put it all back together and it worked fine!