So I have a 2000 Chevy Tracker manual transfer case with manual hubs.  When I try to shift from 2H to 4H, It seems like it is going into gear but the light does not turn on.  I can shift over but will not enter N nor will it go into 4L.  Makes me believe that 4H is not fully engaging.  When turning ignition in the on position I do hear the pump turn on for about 10 seconds.  Checked the shift sheet. So what do you think it may be?

When turning ignition in the on position I do hear the pump turn on for about 10 seconds.

There is probably a leak in the pneumatic freewheel clutch setup - the pump should run for 1~2 seconds at most - the fact that it runs for 10 seconds indicates that the controller is shutting it off because it's not building pressure.

Find the pump, disconnect the hose that leads to the differential and cap it and try again - if it shuts off the pump and turns the light on - the leak is either in the plumbing or the diff - if not it's internal to the pump.  Repeat this at the differential end to determine if the leak is in the plumbing or the diff.