2005 Chevy Silverado Air Conditioning Fan NOT working

First of all, the Air Conditioning works fine and cools the air. The problem is that the fan has stopped working. After some investigation I found a connector on a "small unit" under the passenger side dash that is bolted to the air duct next to where the fan itself is bolted on. The "small unit" has two connectors, one with seven wires that is part of a harness that comes from up in the dash. The second is a red/black pair that hooks to the fan. After feeling the seven wire connector, it was extremely hot to the touch and the black wire insulation was melted and I can see the copper strands are corroded. When I would move the black wire back an forth the fan would come on and then go off. So obviously I've found the problem, but I don't want to just fix the connection, since it seems something is causing this "small unit" to get extremely hot. Hot enough to melt insulation on the black wire. I have some pictures, but this website is having problems uploading. I can email them if needed.