Rrey0456

I'm an owner of a 2005 chevy Cobalt
The a/c went out the other day and I smelt burning I took out the unit and the harness behind it was some what melted and some of the wires are discolored and burnt.
The light blue wire on the fan speed plug Is discolored all the way back to the climate control module blower motor resistor plate.

I took out the climate control module blower motor resister plate and the 2nd and 4th teeth are a rust bunt color but only very very slightly on the tip.

My question is how can I go about figuring out what to replace?
Either the whole harness if so can I just replace the a/c climate control harness seperatly from the rest of the dash's?
Also how can I find out wether I need to replace the climate control module blower motor resister?

By the way I don't know how or why it burnt out/up like it did.