Wells2000

I’m having the exact same issue on my ‘99 Silverado 1500. All the lights are on on the 4x4 switch and it seems to be in limp mode. No codes. I tried replacing the switch and the same issue is still happening. I recently changed the transfer case because the old one was leaking. I’ve replaced the encoder motor as well. Were you ever able to figure out the issue with yours? I have a feeling the mine is true wiring as well. Any help would be greatly appreciated.