When you say nothing happens, do you notice the headlights going out or not when you hit the starter button?
From what you describe, I'd check this sequence:
- Clutch switch - clean if you can. Use a small screwdriver on the underside of the switch to remove it from the housing. I had a switch go bad and had to replace it.
- Starter button and relay - this is chicken and egg first scenario. If the headlights do NOT go out when you hit the starter button, either the switch is fouled or the relay is bad. You can use a voltage meter to check the white/red wire feeding into the relay. When you hit the starter button, you should see voltage on the wire. If you don't then it is most likely the button being fouled. If you do, then the relay is most likely bad. If the headlights do go out when you hit the starter button, then you need to move to the next stage.
Regardless of what your issue it, having a 2005 model REQUIRES that you fit a headlight relay kit such as the Easter Beaver kit. I'm a solid advocate of this. You WILL regret that you haven't if you chose to ignore this.