Alright, guys and gals lets play pin the tail on the eletrical short. I can't figure out what is happening with my whole installation. I going to give an insight and see if any one can see my mistake. The head unit is connected to the original wires that went to the oem head unit. I know I have the right wires (I got the color codes from this site). and from the fire wall I manage to run a 4guage wire from the battery to the cap in the trunk. the cap is a 1.5 farad and from there it goes to a jbl amp 1200.1. Now here is the thing every time that I disconnect the battery and then reconnect it starts sparking.
Another thing that I also noticed is that the plastic on the positive wire near the battery is melted. What other clues should I look for to see what it is?before I forget if I disconnect the cap and then connect the battery it does not do that.

I ve checked the cap and it is ok gooey stuff outta the cap. so it seems ok