4x4 Not Working

[Fireman Crawler]

I have a 2001 F-250 7.3 Electronic 4x4 Manual Hubs. When I select 4x4 it will not engage nor will the lights come on on the dash. I have checked the fuses and all are in working order. What else should I be looking for. It does not click like it is engaging. Any help would be great.

[LOOSEWHEEL]

Check the electrical connector at the transfer case. Known to come loose.