Acid building up on battery terminal

The battery does not seem to be charging on my 1999 Amigo. I put a new battery in the car just to make sure it was not a old/dead battery. Well one day later the car would not turn over. When I opened the hood to jump start it, I noticed white powder (acid) around the red colored terminal. This powder did not come from the battery, but looks like it was produced between the battery terminal and harness. What in the world would cause this? How can I fix it? I would imagine this is part of the cause for the battery not charging? Thanks for the help!