I believe the lockers only activate in 4Lo. I was messing with mine in the snow too and they only stay solid lit up when in 4Lo not 4Hi, I think i saw this somewhere in the owners manual online.

 

Yes, only activated (solid) when in 4-lo unless modded. For some reason mine has recently been showing "ready to arm" blinking light while in 4Hi out of nowhere. Maybe the salt on the road has done something. Perhaps there is a faulty relay in the transfer case...who knows. I'm out of warranty at this point and as long as it works i'm OK for now.