My 2002 Ranger only goes into 4WD low but not 4WD high.

Hey all obviously I am new here so I will say hi and tell a little about me and then I have a question about my truck and hoping someone might have a good answer for me. First I have some working knowledge about mechanics so I wont b totally lost, I have worked around vehicles all may life big and small but now I just drive a big truck so anything I do will b on my own vehicles. I have a 2002 ranger and the 4wd will go into low but not high. Fuses are good, tried tapping on motor at transfer case and still nothing. Any other ideas?

Welcome to this forum! I've renamed your thread, and moved it into the Ranger section.