Ok, so I am at a complete loss as to why my Blazer's 4WD is not working. Here are the details:

When I shift from 2H to 4H or 4L the lights change and stay lit. Nothing like the other posts I have seen where the lights blink and go back to 2H. I have replaced the vacuum actuator, all the switches (front axle and transfer case), the vacuum lines (yes they are routed correctly), and ran diagnostics on the TCCM and encoder motor which there are NO DTCs which mean that the TCCM and encoder motor are functioning correctly.

So, if all these things are working, where could the problem be. The front wheels are NOT engaging which says that the front axle is not engaging (hubs not locking).

I'm at a loss here. Can somebody please help. I live in N. Lake Tahoe, CA and no 4WD is NOT condusive to the massive amounts of snow we get. I have being stuck at home!

Thanks!