Each time I disconnect my battery, I do it the right way: negative first and then positive. However, when I reconnect the battery, I cannot reconnect the positive first and then the negative (right way) because it is doing sparks (small ones) and it is melting the terminal each time (even when I touch it only a few milliseconds). So, I connect the negative first and then the positive (bad way, I am really careful with my wrench though) and I get only a weak spark sound and that's it. Any idea why it is doing this? Thanks.
P.S. I don't know if it change something but my amplifier ground is always hooked up (I had to fix it in a really deep section of the trunk).