AC not working. Not sure where to start.

Symptoms...
Front blower works on all settings, but M2 setting blows at Low speed. (Repair manual definition of speeds is Low, Medium1, Medium2, and High).
AC switch does not work, button light does not illuminate and no evidence at all of any AC system function.

Are these two things related? I read elsewhere on the site that the blower switch influences the AC switch but it was not specific and the wiring diagram in the repair manual is too complex for me to fathom. It sounds like a major expedition into the dash to investigate the front blower switch so I was looking for an opinion or two before embarking.....

jonny