I have a 2000 Dodge Grand
Caravan that had the same problem. The only thing that worked for us was hitting the end of the key quite hard with a shoe (which I kept in the van all the time). It seemed to be worse on cold days too. After about a year of hitting it, it started not working anymore, and finally failed. We ended up calling a locksmith who came to the house and took it apart, greased up the individual....well I can't think of the name, but they are little things that fall into the key's grooves when you put the key in, anyway, we haven't had a problem since. He said that those "things" were getting stuck and when you hit the key with a shoe, you basically vibrate those down to where they should be, "shake them loose". After he lubricated them and loosened them up, they have worked fine. He told us if we could have driven the van to him, he would have done it for 25.00, but it was a little more than that since he came to us. I think only 40 or so. Very cheap way to fix the problem. I would suggest trying a locksmith (instead of a dealer) before you get stuck like we did. I hope this helps!