Just wanted to hop in and say thank you for the detailed posts in this thread. My 4x4 is also not working and this will give me a good place to start.

About 3 weeks ago I noticed the vacuum lines were cut (or appeared cut, both were sliced at the same spot) and after splicing them back together I still can not get 4x4 to engage. I do not get a light on the dash either.

 

You probably have a vacuum leak further up the system. Does your heat work normal and cruise control if you have it?

 

Yes, my heat works great. I've not tried to use my cruise control since the 4x4 stopped working but it worked before hand. Also, my 4x4 worked great right up until the lines were cut.

 

Check out this link, http://www.dodgeram.org/tech/repair/..._engagment.htm

 

Thank you! I actually had that exact page already open in another browser tab but didn't get a chance to give it my undivided attention. Work gets in the way!