full time light flickers on my np242 equpipped jeep

well my transfer case (np242) went out awhile ago so I went to the junkyard and got another one and put it in there and it seems to be working ok accept that when im driving in 2 wheel drive every now and then the green full time 4x4 light flickers on and off for a second. Why is it doing this? How do fix it? After changing the transfer case in a cramped space and having issues with this complex part time full time thing I'm about ready to pull my hair out:banghead:... and the idea of a nice big simple k5 blazer has been going back and forth through my head.
P.S. do what you can because tommorow night I'm taking the jeep out on a date and I would hate for something bad to happen while me and my girlfriend are driving to or back from dinner

Probably your adjustment of the tc lever needs redone.

Also, if your engine and trans mounts are bad it can allow enough twist to the absurd tc linkage to pull things around.