Question about wiper motors or switch???

[crawdad]

I can't get the wipers on my truck to come on. When I turn on the switch (column mounted), I can hear the motor working and the wipers will move a little bit and then stop and start making a grinding sound. If I leave the switch on and get out and pull on the wiper arm a little bit, the blade will come all the way up and back down and then hang up again. Does this sound like a bad wiper motor or what? Any ideas? Thanks.