79 blazer
1/2 ton status
so i was up bright and early to go on a wheeling trip today, and i was doing my pre trip check to make sure everything was in good working order,fluids, bolts tight ect. i have an np-203 with the mile marker part time conversion kit, this was installed buy the previous owner. anyway when i tried to shift the t-case from 2-high it would only go down to 4-high, it wont even go into nuetral let alone the low ranges. i have gotten it stuck in nuetral before due to the shift linkages getting loose and boogered up, but i checked that out and everything was fine. and tried a number of things(even forcing it...
,lol) so any thoughts on whats going on or some stupid thing i might be overlooking? it was working fine a week ago the last time i went to the trails
and has made no noise or indication that anything is wrong i just drove it 40 miles in both 2-high and 4-high and still no sings of anything wrong, the only problem is i cant get that damn stick above 2-high,lol. please help, i would like to try and meet up with my pals later today if possible(wishful thinking). 
,lol) so any thoughts on whats going on or some stupid thing i might be overlooking? it was working fine a week ago the last time i went to the trails
and has made no noise or indication that anything is wrong i just drove it 40 miles in both 2-high and 4-high and still no sings of anything wrong, the only problem is i cant get that damn stick above 2-high,lol. please help, i would like to try and meet up with my pals later today if possible(wishful thinking). 