Hi carpros!
I'm fairly new to the forum and have a question in regards to my 2004 Silverado 1500 z71. Recently my service 4wd message has been coming on my dash. It will go off when I restart my truck and sometimes stay off for a few days but then it eventually comes back on. I noticed when the message appears on my dash the 4wd selector switch on my dash will not work but if I dont have the message displayed then all is working fine. I also noticed the lights on my 4wd selector switch sometimes will go completely out and sometimes it will go to neutral (red light) or even a few times it has gone to 4L. But again if I turn the truck off and then restart it...... all is well. It switches fine to 4L, 4Hi and Auto 4wd when it works and engages well too. I put a new Transfer case in roughly two years ago and I don't suspect this to be the problem. I'm leaning towards a faulty actuator or even the selector switch on my dash. Has anyone had a similiar problem and if so what worked for you?
T

 

Had the same problem and at first thought it may be the ground wires just under driver door on frame. seemed to work O.K. for a short time. Put in new dash switch, no change in problem. Finally changed out Transfer Case Motor and all good. Rockauto.com seems to have the best prices on both parts, both around 2 bills.