Transmission or transfercase Problems with Chevrolet

[edo]

I own a 2002 Chevrolet Tahoe LS. There seems to be a problem with the 4WD transfer case. It will not let me switch between any of the options (2 Hi, Auto 4WD, 4 Hi,4 Lo). In the owners manuel it says that on the dashboard that there should be a signal stating what option it is in but that does not show on mine either. I checked the fuse box and found that one of the fuses was burnt, I replaced it and on the dashboard a light saying Service 4WD showed up. Furthermore, on the switch where the buttons are for selecting which option you want the light does not turn on. I am just wondering if it is an electrical or mechanical problem. My concern is that I do not know what setting the truck is in (Auto 4WD, 2 LO, 2 Hi etc...). If anyone has had the same problem or has any suggestions on what it could be it would be appreciated.

Thank you in advance