First thing I would do is find out for sure if 4-hi is engaged or not. Go find some dirt and spin the tires - it will be obvious if the fronts turn too.
People go through alot of trouble to be able to set up their t-case so it can be put into low gear without 4wd - I don't think that could just happen without some major mechanical failure that you would notice.
Judging by the pics in my factory manual, the switch appears to be on the front of the shifter base.
Best case scenerio: if you find that your 4wd is working, perhaps your first offroad test loosened a bad connection at the switch.
People go through alot of trouble to be able to set up their t-case so it can be put into low gear without 4wd - I don't think that could just happen without some major mechanical failure that you would notice.
Judging by the pics in my factory manual, the switch appears to be on the front of the shifter base.
Best case scenerio: if you find that your 4wd is working, perhaps your first offroad test loosened a bad connection at the switch.