1997 Nissan Pathfinder Heater/AC Blower Switch

The blower fan switch for heat and AC does not work at the I, II, or III speeds, but it works on the IV (highest) speed. The basic fuses look fine. Is the switch bad or is there another "odd" fuse somewhere that allows the IV speed to work but not the slower speeds? If there is an "odd" fuse, where is it?

thanks