I pulled the heater control unit out of my old camaro (now my brothers) because the heater fan would not come on, and basically it didnt work at all (never worked right). Anyways, I found something interesting out, appearently when the temp slider is positioned all the way to "cool" it activated (or deactivates?) some vacuum routing. Does anyone know what this does? I suspect it opens some vent so the cabin is vented even when the heaters (or A/C) is off, though I cannot say for sure. Thanks!

 

It goes to the heater control valve.... opens or closes the coolant flow through the heater core

If the fan won't come on, check the brown wire that leads away from the unit and plugs into the main dash harness. It supplies power to the control head. There is a connector of extremely stupid design that's probably burnt to ashes. Replace the connector with some LARGE insulated slide terminals, it will probably fix it. There's probably nothing wrong with the control head.

 

Naw, problem is 2 fold. The Vacuum thingy that connects to the main selector (vent, defrost, floor...) is very busted, and the Electronic multiposition switch connected to the same selector is melted... New parts on the way, though I am unsure if they are the correct parts!
If they are incorrect, no biggy, AutoZone will refund money (they couldnt tell me for sure when I ordered), and I guess I'll be heading to some Junkyards (hey, maybe I'll find the driver side window control module for my Vic too!)...