Melted ground wire?

I have a Mamba Max and the other day when I was driving and smoke started coming out of my truck. I went to see what was wrong and the ground (brown) wire that goes to the receiver was melted. It had melted all the way up to the receiver was melted. I don't know what to do. I tried to call Castle, but they are closed on the weekends. Thanks.

PS: My setup is Mamba Max, Traxxas VXL, 2s lipo in a crt.5.