Ahhh, here we go again!
Ray,
I've had the same problem with my rig. When you turn the key on, does the 4wd HI light come on at all? Do you hear a 'clicking' sound coming from behing the pasenger side kick panel when you flip the switch? If the light comes on at start up only and there's no clicking sound, you might have a bad motor. Mine had a flat spot and wouldn't engage. Sometimes, I'd have to flip the 4wd switch several hundred times before it would engage, and that could take 45 minutes to an hour. I just had the motor replaced this morning so that I don't get stuck trying to cross the summit in chain control without 4wd!