This same thing almost happened to me on one of my sleds. The sled was warming up while i was gearing up and when i went to plug in my visor, I noticed the (LONG WIRE) wire was very hot. (short wire was on the helmet) A bit longer it would have been GOO. I the realized that the cord was laying on the floor board and was shorting. I am thinking the wires need to be switched, So the outer portion of the connecter is ground.
We are just careful for now with that wire until i check it out.