650 burning up the fan wire?

Took the girlfriend riding today, and it started to smoke. She jumped off so we could check and the fan wouldn't spin and the hot wire going to it was smoking, which was burning the wire coating. The quad then went into limp mode and started letting coolant go through the overflow tube. Shouldn't the fuse have blown before this happened because of a high resistance? Checked the fuse and it wasn't blown. The fan had some dirt and sand in there making it not spin. Anyone else have this problem? Warranty should cover the wire I would assume since the fuse didn't blow before the wire got too hot. Maybe too big of a fuse? I am thinking it was a 20 amp fuse. Cleaned it all out really good and it all works fine now, but the wire bothers me since it is under the protective wrap and I can't really see exactlly where it burnt.