the **** that adjusts how fast your fan blows AC when fizzle this morning when I started up my car. blue electrical smoke and smell came up from right above the ****.

What can I do? Is there a switch that needs replacing?

I'm going to the junk yard tomorrow anyway,how hard is it to swap in a new AC head unit? Or is there some cheap and easy fix to this?

 

The switch is removable from the control head & is replacable by itself. I'd get a new one.

 

ttt,
How do you remove it?

 

Basically you take off the radio trimplate.
Then pull the radio out a little. I can set mine on the passenger seat.
Remove the screws that hold the control panel.
Lower the control panel slightly. (It's held by the pull-wires for the fan ducting.)
Loosen and remove the clip that holds the wiring to the blower switch. Use of needle-nose pliers may help.
Pull out the selector **** from the switch. Be careful not to lose the spring clip that locks the **** in place.
Next remove the switch from the control panel. On my Firebird, there were two 1/4" screws.
Place new switch in the wiring clip. Attach switch to control panel. You could do it the other way, but I found it easier that way.
Then just put everything back together in reverse of disassembly.
The blower switch costs about $8 at the parts store by the way.