I have a 96 lincoln. and early today i had my car locked in the front and the back a little less before locked. i then rode like that for a while. with out the ground being on. then i put the ground back on, to dump it. and sparks started to come out from the metal bar connector. NERALY BURNING MY HAND OF. then i tried putting it back 2 hours later and then it gave me no pronlems. any idea why sparks came out the ground connector?