Originally Posted by woodtrucker

you should put in a posilok and do away with that vac line to the CAD all together. Some folks don't like it but I love it. It doesn't work off vacuum from manifold (I've got a vac leak that I have yet to find causing wild vents but that's another story) It's a pull cable that engages the fork in the CAD and eliminates your chance of popping that hose and loosing 4 wheel drive. Only thing I don't like is you have to rolling at a good clip (>5mph usually) to engage it. Check it out. http://www.4x4posi-lok.com/app_dodge.html
best thing about the posi is that you can drop into 2 wheel low and creep without being in 4 wheel drive. It's great for backing a camper/trailer and such.

The vacuum line going up in front of fire wall should not be open, it should be going to intake manifold. I was just looking at that tonight. On passenger side of intake manifold you have three ports about halfway back. One goes over to pcv on valve cover (passenger side), one is connected to Throttle body and evap canister and the third port will come out of intake and tee off and send one vac line to cruise control and the other will go to another tee and feed the climate control and the 4x4 axle. This link should explain that engine compartment end. Dhvaughan may have you squared away on the Tcase end of things. The van line going to CAD should use intake vacuum to engage/disengage explaining why you can't engage. hope that helps!

Originally Posted by Josh Shaw

hi Iv had the same problems with,my vents switching to defrost when I hit my gas on my truck I took vacuum line the goes to transfer. On passenger side of engine off and took the 3 way off put a 2 way t on it bypassing the vac. Line for transfer case all together. Now have,no problems with my vents at all now