99 4X4 problem
ok so my dad has a 99 f350 (gas of course) and its having 4X4 problems. plain and simple it seems to have gone out. it does have shift-on-the-fly but when he turns the dial inside the cab nothing happens, it doesnt go into 4 wheel drive. also the 4X4 light comes on in the dash when the dial is turned just not engaging. we have been manually locking in the hubs then turning the switch inside and everything works again. all fuses were good, replaced the relay switch and worked for while buts now out again.
any ideas of what the problem may be and any advice to how to fix it would be greatly appreicated.
thanks in advance