4WD NOT ENGAGING

Hi guys I’m stuck in a predicament and looking for someone who might be able to throw out some ideas, 4wd not engaging, transfer case actuators look new and i bench tested them to make sure they were in working condition, but front driveshaft spins freely after trying to engage. Also not hearing the front differential ADD actuator move at all when selecting 4wd, took off front differential actuator and I now have a constant fast flashing 4hi light while driving around in 2wd after reinstalling. So now I cant attempt to engage it if I wanted too, I was told I need to drive between 10-50 to engage 4hi according to the manual, tried it and I heard a clunk the first few times right after selecting 4HI with no success but after I kept trying, the clunk seemed to disappear. it seems like a signal is not being sent to the front actuator and it seems the transfer case isn’t engaging the front driveshaft, I personally don’t want to bring it to a dealer just to have them tell me I need a 6000 dollar transfer case when it could be something more simple, given up on ideas and no forum or group has found a answer for my situation, any help is greatly appreciated