4x4 fuse keeps blowing

I have the truck listed above 1500 classic. the issue I’m having is one day I needed to use 4x4 it is a manual shift system and it wouldn’t work. I checked the fuse and it was blown. so I put new one in it and it worked then while driving it while it was locked in it blew again. I was still able to stay in 4x4 and shift back to 2wd it just wasn’t lighting up on dash but I was skeptical about it not disengaging. so I put new fuse back in to shift it back to 2wd drive no big deal, but today I got stuck so I tried to put new fuse in and it would blow it soon as I tried to put it in. I’ve tried new actuators new shift sensor, looked for broken wires, cleaned up the body ground. I’m lost need help. I know little bit but suck with electrical. it just decided one day not to work and start doing this.