Thanks Stephen, I've been holding off on taking the tools to her because I bought a FSM on Amazon but haven't recieved it yet. I'm hoping to get it today or tomorrow so I can get to work on it this weekend fun, fun, fun.

I recently purchased a '78 as well. The heater controls also did not work. Turned out that it was a split vacuum line that enters the passenger compartment near the battery. Once I fixed that, the controls worked fine.

Having a hand held vacuum pump is really nice for such jobs. They are under $50 for a kit that can also be used for brake bleeding.

Good luck!

John

related question about the non-factory air. is there anything to worry about for it's setup? What does this extra knob look like, and what is it's functionality? what settings does one use to get cold air, theoretically.