Alright, so i have a 2000 Silverado. We've had a lot of snow in the past two weeks. Within the past few days, a lot of frustration with truck. I had to get pulled out (he used my hitch and it wasnt bad) as soon as i noticed after that i didnt have 4 wheel drive. I replaced the selector switch in the dashboard, while new one was in replaced the fuse, realized that fixed it. But not for long. Also have replaced the TCCM and still nothing. I checked the ground wiring.... still nothing. Service 4x4 light is still on. Any other ideas would be greatly appreciated. I currently need to plow more snow we got last night.

 

Well first it sounds like you're just throwing parts at it ... most likely it's a front axle actuator or a transfer case actuator motor. I usually end up using a scan tool to test each of these items individually. Personally, my money's on the front axle actuator.