alternator wiring melting ??

[andrew1219]

I was jump starting car today as I left light on, while jump starting the car the positive cable on my car was touching both the battery and accidentally the metal battery tie down there was a big spark guessing it had to do with touching the battery tie down but now after starting the car the wiring connecting to the alternator is melted and continues to Melt when I start the car any one have any idea what could be causing this ? guessing it has something to do with the positive cable touching the tie down thanks

[MX5Spares]

Thats serious and potential fire hazard.I am not sure what could be wrong but sounds like positive touching negative somewhere.Is the battery fitted correct way around?? We have looms etc but not sure what you will need