[barCruiser]

Sounds like your CDL actuator motor is toast. if your indicator switch is working then it will light up when the cdl is activated. It may "feel" like the center is locking up but its probably not. One way to know for sure is to put it in 4lo (cdl locked) then jack up one front tire and try to turn the front driveshaft. If you can turn the front driveshaft then your cdl is not locked. If you can't turn it then it is locked. As far as a CDL actuator motor is concerned, they run around $500 new from cdan or you could do what I did and try to find one if a salvage truck in the mud classifieds.