Alright so to preface, I know that when you reverse the jumper cables it sends a current into your ground wire and can fry any amount of wiring, but my problem is a bit more complicated. So I was jumping an old tercell with a jump box and accidentally hooked them up backwards, after realizing this I reversed them and tried again to realize there wasn't enough amps in the jump box. So I then jumped the tercell with my mustang, with the correct hookup and it worked fine. A day or.two later my mustang started dying and jumper cables hooked to my mustang would smoke. I'm confused why because there was no current sent through the mustang ground wire and what I need to do to fix it. Thank you.