I did this conversion(https://blazerforum.com/forum/tech-articles-diy-29/how-homemade-posi-lock-cable-system-31138/ ) on a 1997 Blazer.
and you can hear the axle click in but when testing you get no power the front wheels.
Is there anything else to check?
Thanks Brad

 

bump up for help

 

It is possible that you have a problem internal to the front axle. You can check to see if the front axle is engaging by jacking up the passenger front wheel, leaving the driver front on the ground. With the transfer case in 4HI or 4LO and the front axle engaged, try to turn the passenger wheel. If you hear/feel clicking, then the collar inside the front axle is not properly engaging the passenger side axle. If the front driveshaft turns, then the transfer case is not properly engaging 4wd.