follow the vac line from the intake manifold down to the top of the t-case, where there is a switch. from there follow 2 lines to the cad.

....or just buy a posi-lok and be done with it.

 

What is a posi lok?

 

Test for vacuum at the switch. Just put the supply line on there, and have a friend switch into 4wd. see if the vacuum switches ports, and how strong it is.

 

Here is a really good place to look, find the lines that run on the inside of the frame and where it is about 2 inches or so from the passenger side exhaust manifold and for some stupid *** reason has a factory bend AWAY from the frame that actually puts it closer to the exhaust. no joke i had a problem where i couldnt get the front hubs to disengage hardly because that line was completely melted, being aluminum. you might have the other line on yours with a hole melted in it there.

 

google is your friend on this. google Central Axle disconnect, grab a coffee and start reading you will answer your own questions!

 

its what you install after you get tired of screwing around with that stupid cad.
https://dodgeforum.com/forum/2nd-gen...installed.html