Toyota Repair: 4WD front-back lock, snowy mountains, 4wd system

Question
Ted -

Thanks for all your valuable postings - you're very generous and helpful.  Quick question...(hopefully).  I just went up to the snowy mountains and pressed the front-back 4WD lock button on the middle/dash console of my 1999 Toyota Landcruiser.  Unfortunately, no light illuminated on the dashboard (I seem to remember a light should come on).  Is there a quick way to tell if it's simply a burnt out indicator bulb or whether my 4WD system needs to be checked?

Answer
You should be able to tell if it goes into 4x4 mode, if not you will lose traction to the front wheels, the 4x4 light is turned on by a switch in the front differential, if the differential engages the hubs then the light should come on, there may be a problem with the front differential actuator.