You have two possible issues, the switch lighting and it operating, both being controlled through the "Switch Pack Module". The "Recirculation Switch" actually closes off outside air into the system by way of an actuator in the air intake. A "VERY" simple solution, to assure using only interior conditioned air is to tape over the two air intakes in the nose, which is the same (maybe better) than operating the "Recirc. Switch"
BTW, I am doubtful that you could notice the difference even if the switch was operating correctly. Additionally, only using inside air has no disadvantages, especially in the AC mode.
Cheers,
Michael