My '98 did the same thing. I did find one of the solenoids on the firewall bad. Removed, tested and it absolutely was bad. I replaced it, then it would only actually go into 4 wheel drive when the temperature was below about 35 degrees. And, the lo-range light would never come on. Finally, removed the switch on front of transfer case, checked it, , , even put it in the freezer to cool down and then check the continuity and it proved to be bad. Changed and all works as it should now. My switch, unfortunately, cost $52.00, but it's fixed now. I also lubricated the mechanism on the differential motor. Also, the lo-range light now comes on.
Last edited by a1topflite; 03-16-2013 at 10:09 AM.
Reason: Not finished.