Catchy title, eh? I recently did a motor swap on my bike. Before doing it - my fan use to come on at the halfway mark on the temp guage. Now, after swapping, the fan won't come on at all. I've verified that my fan works. (Hooked it to the battery). I verified that there is power going from the right side to the left side of the bike (from the switch plug on the right side to the left side where it plugs into the fan). I verified that the cooling fan switch DOES work. It closes in the same place as it used to, about halfway up the guage. Just hooked an ohm meter to it and waited for it to close. If I stick a pair of needle nose pliers into the plug on the right side of the bike (the plug that the switch goes into) the fan comes on. I also just plugged in one side of the switch, and measured voltage coming out of the other side of it, and It was the same 12v that was going in. So there doesn't appear to be a power loss through the switch. Still, no fan when the switch is closed and everything is plugged together. Anybody have an idea? Everything is working, everything is getting power, contacts are good, but still no fan when plugged together. I'm stumped. Thanks!