My manual sliding door on my 2002 dodge grand caravan stays locked and

"Can you open it at all?

if you can from the outside but not the inside, your child lock is on. There should be some small switch on the door, near where it latches to the rest of the car when its closed.

If not, does it open when you pull the manual lock inside the car up?

If it does, then your fine and there is no issues.

Hope this helps! If it did please hit the accept answer button!"