I was thinking about straight wiring the fan to an ignition switch wire so the fan comes on with the ignition on. Which wires do I need to hook to? Also do I need to put a toggle switch in line or just straight wire it?

 

why?

 

What year is the bike?

I would definately use a relay to lighten a load. Let me know and I can try to help you with a diagram.

 

I would just wire it to a switch instead of the ignition. Just turn it on yourself, you dont really need it when you are on the highway.

 

i did this to my f4i stunt bike. i tapped into the tail light from the thermo. it works and will not drain the battery since the tail light is an accesorry. the only reason i did it to my stunt bike is because i dont go fast enough for air to flow through the radiator.

 

Don't do it on a street bike. No reason to run the fan all the time. If your temp sensors are working properly the ECU will turn on the fan when you need it.