If I can get my hands on a DVOM, what steps would I take with it depending upon the readings I get? How difficult would it be to replace the climate control assembly if you think this is the problem? Would hate to go to the expense of this unit if you think it might be something else.
Here's some additional info to help you with the diagnosis.
The climate control unit has 3 rotary knobs. Left is for fan speed, center for temp, and right for vent selection. Below the left fan speed knob are two buttons - one for exterior air circ and the other for interior air circ. The right vent selection knob apparently works fine because it automatically causes the air circ button lights to switch from one to the other depending upon the vent selected.
Below the right vent selection knob are also two buttons - one for a/c and the other for rear window defroster. The rear defroster button works fine because it lights up when I push it. The a/c button is not activating/lighting, but then again the fan is not running.
Hope this helps with more insight. Thanks.