the side foot well blowers are only controlled by the autoheat control between the seats.
if you hear the servo motor in the autoheat(AH) run for a few seconds then stop and the fuses are good, there are 2, and no fans at all either the motors are locked up or the 12v supply microswitch in the AH is bad.
I did I thread on swapping switches in the AH controls to fix this problem or you can order a new microswitch.
http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/941050-auto-heat-foot-well-blowers-part-deux.html