1997 Chrysler Town and Country LSI 3.8, Automatic 120k miles Wipers motor wont Move wiper arms.

1997 Chrysler Town and Country LSI 3.8, Automatic 120k miles, Central Florida.
I replaced my windshield wiper motor. After I checked that the motor works I put the wiper arms on and it quit working. I checked the nuts that hold the arms on, then I took it all apart and put it back together again. I had to be sure it was not an error on my part. The same thing happened. Actually I only need to put one arm on for it to stop working. You can hear the motor working it just does not seem to be able to move the arms. When I take them off it works again. Before I had to replace the motor, every once in a while the wipers would not turn off until I turned the motor off.