2012 caravan sliding door opens but will not close

SOURCE: 2000 grand caravan sliding door won;t open

I would start by pulling the door panel off the inside. This will give you a look at the lock and handle mechanism to see what is amiss. Suspect a broken, fallen link that may now be lying in the bottom door channel and retrievable with magnetic pick-up tool. Get a good trim removal tool since a panel that large is easy to mar if you try pulling it with a screwdriver. Have a helper assist with the job and start by pulling the rear and middle seats if you can. To cheat on this, you may want to pull the panel on the opposite door to see how everything is supposed to look.

SOURCE: dodge caravan sliding doors

First, keep in mind that as you begin to remove these doors you run the risk of causing serious scratches to the paint and glass, so put some masking tape and/or plastic sheeting around both sides of the door (rear quarter panel and rear glass, front door and front door glass)
I would get a Haynes repair guide since that's what I have to work from and it will tell you step by step with pictures, what to do. It's not hard, but you need to get all of the attach points unhooked to be successful. Suggest you have a helper working with you to keep the door steady.

SOURCE: 2005 dodge grand caravan sliding door problems

could be a partially broken wire in the wiring harness that runs in the door track. the wires are inside what looks like a plastic chain that allows it to move with the door and have seen them partially break not allowing power to flow the whole time

SOURCE: Power sliding door doesn't work!

Try taking off the door, or spray some wd-40 on the rail. It sounds like its either not getting enough power or its getting caught on something.