Melted Ground

Tonight i was running my Erevo.I am running 2 Kershaw Design 700 HO,s with the Traxxas EVX2,Novak 2s Lipo cut off and 2 SPC 8000mah lipos.I have about a dozen runs and never had a problem.Today i ran it till i got the usual acceleration stutter warning me the voltage is getting to the warning zone.I have done this since it was installed and my cells are never lower than about 3.25 to 3.40 per cell.But when i stopped today all was fine then i turned the speed controller off and the ground wire was cooked.Any ideas.Its melted from the LVC to the ESC???Now im not sure what the problem was and if my LVC is anygood now..