After a bunch of research and hunting I believe this is called the defroster switch and not the fan master on/off switch?
62 Starfire w/air. It is located on the metal ducting, had two wires going to it, blue and black.


Pretty burnt, I think PO had a toggle bypassing it.
Thanks for your help.

 

That looks more like a rheostat than anything else. If that is the case, then it would be sending a variable DC voltage to something else depending upon the physical position. This would make the fan operate at a variable speed.