4X4 Not Working

[99fx4]

Hey, my dad has a 2002 F-150 and the 4x4 wont go on,, the light in the dash goes on but the front wheels dont turn, its the same if he tryes to put it in 4 low. its a floor shifter, not sure if it could be the cable, I checked the fuses and they seem good.

Has any one have this prob??

Thanks

[shelbyx1]

could be a problem with the vacc control system for the front diff lock,just see if you are getting vacc signal to the diff actuator.

[99fx4]

ok, thanks ill check into that

Thanks,