Here are all the parts you need. I assume that you have the grips and what looks to be the correct switch but what you might be missing is the harness for the grips(part #3 in the diagram above). I took a picture of all the parts you need and the numbers correspond to the part numbers in the diagram:
Part 3(the grip harness) is from a R100GS here is a picture of the part tag:
I hope this helps.