New to the forum... New to XJ's...

I recently purchased a 93 XJ with 6.5" lift, stock diffs, 4.6 stroker, 34" tires...
When I tried to shift my transfer into 4Lo today it still had the part time light on the dash like it was still in 4Hi. Worked fine yesterday which was the first time I had to use it. Could the linkage be out of adjustment and if so how can I adjust that...???