Another 4x4 wtf...
 

I go to pull a friend of mines dodge ram out of a swam today, flipped the switch for 4x4, and NOTHING HAPPENED!!! No click no light nothing. I popped the fuse box, jiggled a few fuses, and the A4WD light flickered on, but nothing for the 4H or 4L. What the hell is wrong with it now? I havent had it locked it about a months time... Stupid electronic shifting

can't say much to help you, but I saw you mentioned the AWD system light. What exactly is this truck equiped with for the awd/4x4 system? I know some vehicles that have an awd system only engage when the computer senses a lack of traction. All the switch could be doing is turning on that particular sensor. Also my truck has a damn switch and if what I said above doesn't fit, then you'll just have to trace the electrical. Sorry to say but switches suck.

2wd, A4WD, 4HI, 4LO are my options...

Okay, looks like the 4x4 options are for exactly that, and the AWD is for when you want the computer to make the desicion. The one time I had a problem with my system engaging. I just shut of my truck and turned it back on and it worked after that. Unfortunalty I'm not the greatest with electrical, more of a mech. myself so all I can say is if it's under factory warrenty take it in. If not, get some specs from a manual or ofline, and get to testing. Also does the front axle engage ever when the system is in AWD? If not, then there could be damage both electrical or mechanical at the front driveshaft, or transfer case. Hope you can figure it out!

no 4x4
 

Had the same problem and it was a vacuum motor thats on the transfer case. It cost like $200 and the mechanic installed it for $75. I kept getting gear grinding. It looks like a cone shaped plastic with a brass rod thats screwed in to something down there!