1997 f250 4x4 problems

[meow700]

Let me start out by saying i know there are a million posts discussing this system however i cannot find one that relates to my problem. My 4x4 does nothing when the switch is flipped no clicks no nothing EXCEPT if i flip it to 4x4 and disconnect and reconnect battery it will go into 4x4 ONCE (even front diff will lock) then will be stuck in 4hi until i flip switch to 2wd and disconnect/reconnect battery. Also i have another truck that i was able to borrow a few parts from just to rule out those components. I tried another 4x4 relay module (one in top of dash). Took GEM out no corrosion anywhere no signs of a short everything else on truck works great. Tried a different 4x4 switch, and a different shift motor. Thank you for any direction and or ideas