2001 4x4 won't engage

When I rotate the knob, nothing happens, the control module doesn't even make the clicking sound. I recently had the tires rotated at Sears, took it back they said it wasn't their problem. I found the control module on the passenger side behind the kick plate, all the connections are good. The light bulb behind my tach burned out awhile back but all other lights function in the dash. I would assume that the problem is somewhere inside the cab of the truck before the control module but would love any suggestions someone can offer. Thanks in advance.

i had the same problem with my '96 ranger when i bought it. the 4x4 light would come on, and i could barely hear it trying to engage, but the hubs ended up being no good, which is common with the automatic locking hubs.